I have a site whose content is written in AsciiDoc, using the [jekyll-asciidoc][] plugin.

Just the Docs works great, but there are just two minor styling glitches I've noticed:

The first is that Just the Docs' CSS doesn't understand the code block markup jekyll-asciidoc produces.  It's not too different though, so it's very easily fixed.

The second is that jekyll-asciidoc generates `div.sect(𝑛 − 1)` elements around headings of type `h𝑛`, that enclose all the heading and all the content after it until the next heading of greater or equal rank.

This means that headings are _always_ first children in AsciiDoc output, which meant the wrong margins were applied to most headings. To fix this, we need to only reduce the margin of first-child headings nested directly below the .main-content element, and headings nested directly below AsciiDoc `.sect𝑛` elements that are themselves first children.

With these two small changes, my site looks perfect, and the styles look exactly the same as on Just the Docs' own documentation.

[jekyll-asciidoc]: https://github.com/asciidoctor/jekyll-asciidoc

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

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

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>

Fix #417

- Avoid appearance of dark border around visited code links in Safari.

Optimised CSS selectors.
Changed markup in `linenos-test` to inhibit line numbers appearing in YAML examples when testing code fences.

The additions to `_config.yml` go together with the changes to `code.scss`,
to facilitate adjusttments by users. See `docs/linenos-test` for the details.
The CSS code has been significantly refactored and simplified,
and seems to produce sensible results (at least on Safari and Firefox).

Removed some comments and layout

Produces sensible (but not perfect) results from different kinds of highlight markup.
The CSS code needs a major refactoring to eliminate duplication and superflous lines.

Fixed more layout details. Numbers of selectors still to be fixed.

Correected layout, order, values.

The added examples in `docs/index-test.md` extend the previous examplees of highlighting, documenting the required inout.