* implements search placeholder configuration

* changes implementation approach to use search_placeholder_custom

Thanks to @pdmosses for the suggestion!

* strips whitespace and HTML for both placeholder and aria-label

Fix #685
- Wrap scss file in comments with `{% raw %}` and `{% endraw %}` tags

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

Fix #517

Users expect nested task lists to have the same indentation as other lists.
Fix the styling in `_sass/content.scss` to do that.
Add examples in `docs/index-test.md` to test.

As is, this is invalid and will not cause the TOC to be rendered. The collapsing example is fine.

Co-authored-by: Matt Wang <matt@matthewwang.me>
Co-authored-by: Peter Mosses <18308236+pdmosses@users.noreply.github.com>

These docs outline some of the custom includes that are provided by the theme and can be modified by the user.

Co-authored-by: Matt Wang <matt@matthewwang.me>
Co-authored-by: Patrick Marsceill <pmarsceill@users.noreply.github.com>

This PR combines (and resolves conflicts between) #448, #463, #466, #494, #495, #496, #498, and #572. 

The main aim is to facilitate use of several of the implemented features _together_, when using the fork as a remote theme. It should also simplify merging the included PRs into a future release.

The branch [combination-rec-nav](https://github.com/pdmosses/just-the-docs/tree/combination-rec-nav) adds [multi-level navigation](https://github.com/pmarsceill/just-the-docs/pull/462) and (NEW:) [sibling links](https://github.com/pmarsceill/just-the-docs/pull/394) to the branch used for this PR. It includes updated [documentation for the navigation structure](https://pdmosses.github.io/just-the-docs/docs/navigation-structure/), and reorganised and extended [navigation tests](https://pdmosses.github.io/just-the-docs/tests/navigation/). The documentation and the tests can be browsed at the (temporary) [website published from the combination-rec-nav branch](https://pdmosses.github.io/just-the-docs/

).

_Caveat:_ The changes to v0.3.3 in this PR and #462 have not yet been reviewed or approved, and may need updating before merging into a release of the theme. If you use a branch from a PR as a remote theme, there is a risk of such updates affecting your website. Moreover, these branches are likely to be deleted after they have been merged. To avoid  such problems, you could copy the branch that you want to use to your own fork of the theme.

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

Bumps [prettier](https://github.com/prettier/prettier) from 2.5.1 to 2.6.2.
- [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/2.5.1...2.6.2

)

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

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

This is one solution for #798, namely that `webrick` is needed as an explicit dependency for Ruby 3+.

Closes #798.

updates Code of Conduct to Contributor Covenant v2.1

See - https://www.contributor-covenant.org/version/2/1/code_of_conduct/

* Set color for search input

Fix #497
- Insert `color: $body-text-color;` in styling for `search-input`.

* Update search.scss

Prettier

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

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

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

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

Bumps [prettier](https://github.com/prettier/prettier) from 2.1.2 to 2.5.1.
- [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/2.1.2...2.5.1

)

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

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Add VScode devcontainer

Upgrade to GitHub-native Dependabot

Bumps [ajv](https://github.com/ajv-validator/ajv) from 6.10.0 to 6.12.6.
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](https://github.com/ajv-validator/ajv/compare/v6.10.0...v6.12.6

)

---
updated-dependencies:
- dependency-name: ajv
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Bumps [path-parse](https://github.com/jbgutierrez/path-parse) from 1.0.6 to 1.0.7.
- [Release notes](https://github.com/jbgutierrez/path-parse/releases)
- [Commits](https://github.com/jbgutierrez/path-parse/commits/v1.0.7

)

---
updated-dependencies:
- dependency-name: path-parse
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Bumps [ini](https://github.com/isaacs/ini) from 1.3.5 to 1.3.8. **This update includes a security fix.**
- [Release notes](https://github.com/isaacs/ini/releases)
- [Commits](https://github.com/isaacs/ini/compare/v1.3.5...v1.3.8

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>
Co-authored-by: Patrick Marsceill <pmarsceill@users.noreply.github.com>

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.19 to 4.17.21. **This update includes a security fix.**
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](https://github.com/lodash/lodash/compare/4.17.19...4.17.21

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>
Co-authored-by: Patrick Marsceill <pmarsceill@users.noreply.github.com>
Co-authored-by: Matt Wang <matt@matthewwang.me>

[Security] Bump hosted-git-info from 2.7.1 to 2.8.9

Fix images in Markdown kitchen sink

Changed small-image to match large image and fix reference

Renaming the large image and changed the index test references to display these images

Remote image here is not loading - https://just-the-docs.github.io/just-the-docs/docs/index-test/#large-image

via https://www.flickr.com/photos/97810305@N08/9401451269

[Security] Bump y18n from 3.2.1 to 3.2.2

Fix image link not working