This adds a parent selector, `rendered_content`, to night mode syntax
lighlight selector. This helps us in getting the "day mode" syntax
highlight styles in night mode.
This commit transitions all styles in app.css in the Django pipeline
to being compiled by webpack in an app-styles bundle, and renames the
various files to now be processed as SCSS.
To implement this transition, we move the old CSS file refernces in
settings.py and replace them with a bundle declared in
`webpack.assets.json` and includedn in the index.html template
Tweaked by tabbott to keep the list of files in `app.css` in
`webpack.assets.json`, and to preserve the ordering from the old
`settings.py`.
Anders Kaseorg
Vaibhav
Cynthia Lin
Aditya Bansal
Armaan Ahluwalia