This uses scss mixins, this are functions you can pass parameter in it and
return css/scss. It made repeating vendored transistion, and user-select property
more easier to use with less repetation. This also includes a scss file called reuseable_components.scss
which can be used anywhere else.
We only use this data in a rarely-used settings screen, and it can be
large after years of posting screenshots.
So optimize the performance of / by just loading these data when we
actually visit the page.
This saves about 300ms of runtime for loading the home view for my
user account on chat.zulip.org.
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`.