This is an alternative PR that resolves #1011. Unlike #1013, this PR defines a *new* SASS file, `_sass/custom/setup.scss`, specifically designed for new custom variables (and other SASS-only constructs). It's imported after our `support` SASS files are (functions, variables), but otherwise is imported before all other files (ex, when CSS is emitted).

So, custom callout colors can now be defined in this file. I also move the custom callout colors present in `custom.scss` to the right location.

I've added some docs that briefly explain how to use the feature. Feedback is welcome!

---

As an aside, I chose not to add a `_includes/css` file that imports this, and then import that file. I think that's only necessary if we're trying to render liquid somehow in the SASS file; since we're not trying to do that for `setup.scss`, I've opted to not include it. If we think this is relevant, I can re-add it.

Co-authored-by: Peter Mosses <18308236+pdmosses@users.noreply.github.com>

Bumps [prettier](https://github.com/prettier/prettier) from 2.8.2 to 2.8.3.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/main/CHANGELOG.md)
- [Commits](https://github.com/prettier/prettier/compare/2.8.2...2.8.3

)

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updated-dependencies:
- dependency-name: prettier
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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This is a prototype for review and discussion. My use and testing of this PR is on top of 6d9d4135. The changes are trival to rebase to `main` and I'm happy to do so if this prototype moves forward.


* Feature request details in linked issue, fixes just-the-docs/just-the-docs#1067
* I welcome feedback and all discussion
* A draft doc site of mine using this PR is at https://docs.hidale.com/

To use the prototype, the two include files need to be customized. Here are mine from the draft website https://github.com/diablodale/dp.docs/commit/9c0d836408af2e72dbce115a01ce6627137e66dd



Co-authored-by: Matt Wang <matt@matthewwang.me>

In touching up the migration guide, I noticed that many of our documentation site links are broken! For example, on the homepage, this link:

<img width="782" alt="screenshot of homepage; code snippet is in next block" src="https://user-images.githubusercontent.com/14893287/210462690-31aa7bf5-dd79-4e8f-a3c5-1213e73771c4.png">

which has the following href

```code
<a href="/just-the-docs/just-the-docs/CHANGELOG/">the CHANGELOG</a>
```

duplicates the `baseurl` twice. There are 14 such broken links across the site. Each link duplicates the `baseurl` and `link` tags, which has since been resolved with links being relative by default (there's a set of PRs that document this - I can't find the exact paper trail right now).

To resolve this, I:

- find and replace site-wide `{{ site.baseurl }}{% link` with `{% link`
- tested each link, which now works properly locally *and* on the deploy preview

I'm surprised we didn't catch this earlier! I also could be missing something else, in which case feedback on this PR is certainly welcome.

The typography utilities page has been moved sopme time ago, but the button URL was not updated. This commit fixes the broken link.

This PR simply fixes a few spacing and comment nits I found.

Bumps [prettier](https://github.com/prettier/prettier) from 2.8.1 to 2.8.2.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/main/CHANGELOG.md)
- [Commits](https://github.com/prettier/prettier/compare/2.8.1...2.8.2

)

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This PR corrects the change to `/_sass/search.scss` made in 551398f9. This change tried to set the `padding-**top**` property to **two** values rather than set the `padding` property to these values (to represent the vertical and horizontal padding values).

I just reviewed 551398f9 and believe that this should be the other half of the fix proposed by just-the-docs/just-the-docs#1104.

This is a follow-up from a private maintainer discussion (https://github.com/orgs/just-the-docs/teams/maintainers/discussions/11?from_comment=12). The cliff's notes for the public are: we believe we are not currently GDPR-compliant in how the docs site itself serves analytics.

For now, we'll disable analytics; we don't use them anyways. We will then:

- add analytics and the relevant banner to the regression test repository
- in the future, workshop a built-in solution for JtD users to be GDPR compliant
- optionally, clarify the role of users of this theme (their responsibility is to make their sites GDPR compliant)(

Hi everyone, this is a large refactoring PR that looks to **modularize site components** following the discussion in #959. At the top-level, it:

- moves icons, the sidebar, header (navbar, search, aux links), footer, and mermaid components of the `default` layout into their own `_includes`
- creates a new `minimal` layout that does not render the header or sidebar as a proof-of-concept for the composability of components
- documents all existing and new layouts (including vendor code) in the "Customization" section 

An important goal of this PR is for it to be **just code motion and flexibility**: there should be **zero impact** on the average end user that only consumes the `default` theme.

The next few sections go in-depth on each of the listed changes.

### new components

The `default` layout contains a "list" of all relevant components. Importantly, some of these components have sub-components:

- the header is split into the search bar, custom code, and aux links
- the icons include imports different icon components, some of which are conditionally imported by feature guards

There are also candidates for future splits and joins:

- the sidebar could be split into navigation, collections, external link, and header/footer code
- the "search footer" could be joined with other search code, which would make it easier to "include search" in one go; *however, this is a markup change*
- @kevinlin1 has pointed out that there is some leakage between the sidebar (which computes parents/grandparents) and the breadcrumbs (which needs them to render). He's graciously added a bandaid fix to `minimal` (which does not render the sidebar). However, in the long term, we should either:
    - calculate this in a parent and pass the information to both components
    - change how this works entirely (which may happen with multi-level navigation)

@pdmosses has done a great job outlining this and more in his [Modular Layouts test site](https://pdmosses.github.io/modular-layouts/docs/main/).

### minimal layout

Based on @kevinlin1's use-case in just-the-class (see: his [Winter 2023 CSE 373 site](https://courses.cs.washington.edu/courses/cse373/23wi/)), we've created a first-class `minimal` layout that does not render the sidebar or header.

In a [comment](https://github.com/just-the-docs/just-the-docs/pull/1058#discussion_r1057015039), Kevin has indicated that we can re-add the search bar in the minimal layout; however, it seems like this would be a code change. I think we should punt this to a future issue/PR.

@pdmosses has also discussed the confusion of `minimal` as a layout and its meaning in inheritance. I've added a note in documentation to clarify the (lack of) inheritance relationship.

### documentation

I've written documentation in the "Customization" page / [Custom layouts and includes](https://deploy-preview-1058--just-the-docs.netlify.app/docs/customization/#custom-layouts-and-includes) section explaining:

- generally, that we use includes/layouts (and pointing to docs)
- the `default` layout and its constituent components (with a warning about name collisions)
- creating alternative layouts with `minimal` as an example
- the inheritance chain of layouts and the vendor layouts that we consume

I've also created (and linked to) a [minimal layout test](https://deploy-preview-1058--just-the-docs.netlify.app/docs/minimal-test/) that is currently a copy of the markdown kitchen sink but with the minimal layout. I think there's room to improve this in the future.

### future work

I think there's a lot we can do. Let me break this into various sections.

Potential follow-ups before `v0.4.0`:

- re-including search in `minimal` (anticipating a minor code change)
- fixing the leakage of parent/grandparent information between the sidebar and breadcrumbs (anticipating no end-user code change, but good to evaluate separately and discuss)
- heavily document this in the migration guide (#1059) and in our RC4 release docs
- improve semantic markup for components (ex `main`, `nav`)

Related work in later minor versions:

- split up components into smaller components
- allow users to easily customize new layouts using frontmatter (see @kevinlin1's [comment in #959](https://github.com/just-the-docs/just-the-docs/issues/959#issuecomment-1249755249))

Related work for `v1.0` (i.e. a major breaking change):

- rename and better categorize existing includes
    - standardizing the "custom" includes
    - moving other components to the `components/` folder (ex `head`, `nav`)
    - potentially: less confusing naming for various components
- potentially separate the search and header as components, so that they are completely independent 

Tangentially related work:

- more flexible grid (see @JPrevost's [comment in this PR thread](https://github.com/just-the-docs/just-the-docs/pull/1058#issuecomment-1363314610))
- a formal [feature model](https://en.wikipedia.org/wiki/Feature_model) of JTD, documenting feature dependence (see @pdmosses's [comment in this PR thread](https://github.com/just-the-docs/just-the-docs/pull/1058#issuecomment-1365414023))
- better annotate new features (motivated by writing these docs)
    - we should add "New" to new features :) 
    - we should note when a feature was introduced (I think this is a core part of most software documentation)
    - we should annotate things that are "Advanced" in so far as the average Just the Docs user will not use them / they require significant Jekyll knowledge


--- 

Closes #959.

Context: https://github.com/just-the-docs/just-the-docs/pull/1029#issuecomment-1369613443.

This PR fixes three bugs:

# first bug

When revising my last PR #1086 I realised a slight bug in the code-copy PR #945 , my change to the css ignored a case. This PR is a hotfix and

Before PR #945:
![image](https://user-images.githubusercontent.com/26844016/209864912-2fe8e5a9-f21e-40c7-aa0d-65050196f4ee.png)

![image](https://user-images.githubusercontent.com/26844016/209864950-c315cef1-36ee-4356-91b2-db159cf3806f.png)

After PR #945:
![image](https://user-images.githubusercontent.com/26844016/209864524-70a8b095-056a-464b-9ff7-fd31397492ba.png)

![image](https://user-images.githubusercontent.com/26844016/209864558-9fd7a5d3-a965-4aa4-af62-a56846e331b3.png)

Fix:
![image](https://user-images.githubusercontent.com/26844016/209865514-a9921096-b852-4402-8272-b76908851ad6.png)

![image](https://user-images.githubusercontent.com/26844016/209865550-d7842507-74fc-4f21-b407-9b8917df1fd8.png

)

# second bug

> @simonebortolin @mattxwang I'm trying to write some regression tests for this feature.
> 
> If I use GitHub's copy button to copy the following plain text, it preserves all the spaces:
> 
> ```
>  1 leading space
>   2 leading spaces and 2 trailing spaces  
> 3   internal spaces
> 4 trailing spaces    
> ```
> 
> Using the new copy button with the same text in this PR branch of JTD gives this:
> 
> ```
> 1 leading space
>    2 leading spaces and 2 trailing spaces  
>  3   internal spaces
>  4 trailing spaces
> ```
> 
> It appears that the leading space from line 1 has been removed, and inserted on all the other lines. Moreover, the 4 trailing spaces have been removed.
> 
> BTW, #924 didn't give a precise requirements spec, but mentioned the Microsoft docs UI; @mattxwang mentioned also the GitHub UI. It would be helpful to add a functional spec of what the JTD copy button is supposed to do, as a basis for regression tests.
> 
> I'm not aiming at a rigorous test for the UI. Personally (using Safari at the default mag) I find the clipboard icon too small: it just looks like a box, and I can hardly see that there is a clip at the top. But I don't have a suggestion for a better icon.

# third bug

When I re-read the code after the second bug, I noticed a bug that it does not always select the text field to be copied correctly  (in case there are also line numbers) is copied:

```
1
2
3
4

	
# Ruby code with syntax highlighting and fixed line numbers using Liquid
GitHubPages::Dependencies.gems.each do |gem, version|
  s.add_dependency(gem, "= #{version}")
end
```
instead of 
```
# Ruby code with syntax highlighting and fixed line numbers using Liquid
GitHubPages::Dependencies.gems.each do |gem, version|
  s.add_dependency(gem, "= #{version}")
end
```

Co-authored-by: Matt Wang <matt@matthewwang.me>

This PR corrects the change to `/_sass/labels.scss` made in 551398f9. This change tried to set the `padding-**top**` property to **two** values rather than set the `padding` property to these values (to represent the vertical and horizontal padding values).

* Fix stylelint "declaration-block-no-redundant-longhand-properties"

Co-authored-by: Matt Wang <matt@matthewwang.me>

Bumps [stylelint](https://github.com/stylelint/stylelint) from 14.16.0 to 14.16.1.
- [Release notes](https://github.com/stylelint/stylelint/releases)
- [Changelog](https://github.com/stylelint/stylelint/blob/main/CHANGELOG.md)
- [Commits](https://github.com/stylelint/stylelint/compare/14.16.0...14.16.1

)

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Avoid the need to add a link to favicon,ico when editing `_includes/head_custom.html`, and avoid creating an invalid favicon link

- Remove the content of `_includes/head_custom.html`
- Add code to `_includes/head.html` to create a link to an existing favicon,ico
- Add an explanation of favicon_ico to docs/configuration.md
- Remove the example of `includes/head_custom.html` and add an explanation of what the `<head>` element automatically includes

Avoid Liquid failure when no pages with titles

Fix issue #1085

The user's config specified collections (incorrectly). Trying to build the site resulted in Jekyll failing due to a Liquid error. The error report did not suggest the cause of the error.

Liquid fails with division by 0 when title_pages_size is 0. This fix guards that code by checking that title_pages is non-empty.

To test:

1.  Specify a Jekyll collection with no pages, and specify it as a JTD collection.
2. Build the site.
3. Check that the specified collection has no nav links to pages.

Fix two bugs in customization docs

- custom favicon docs were not wrapped in `{% raw %}` tags
- the "new" annotation for color schemes had an extra whitespace, and so the CSS class was not applied