Add settings to rustdoc to use the system theme
This PR adds new settings to `rustdoc` to use the operating system color scheme.
`rustdoc` actually had [basic support for this](b1af43bc63/src/librustdoc/html/static/storage.js (L121)), but the setting wasn't visible and couldn't be set back once the theme was explicitly set by the user. It also didn't update if the operating system theme preference changed while viewing a page.
I'm using [this method](https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queries/Testing_media_queries#Receiving_query_notifications) to query and listen to changes to the `(prefers-color-scheme: dark)` media query. I kept the old method (based on `getComputedStyle`) as a fallback in case the user-agent doesn't support `window.matchMedia` (so like... [pretty much nobody](https://caniuse.com/?search=matchMedia)).
Since there's now more than one official ""dark"" theme in `rustdoc` (and also to support custom/third-party themes), the preferred dark and light themes can be configured in the settings page (the defaults are just "dark" and "light").
This is also my very first "proper" PR to Rust! Please let me know if I did anything wrong :).
For sub-items on a page don't show cfg that has already been rendered on
a parent item. At its simplest this means not showing anything that is
shown in the portability message at the top of the page, but also for
things like fields of an enum variant if that variant itself is
cfg-gated then don't repeat those cfg on each field of the variant.
This does not touch trait implementation rendering, as that is more
complex and there are existing issues around how it deals with doc-cfg
that need to be fixed first.
Remove disambiguators from intra doc link text
Closes https://github.com/rust-lang/rust/issues/65354.
r? @Manishearth
The commits are mostly atomic, but there might be some mix between them here and there. I recommend reading 'refactor ItemLink' and 'refactor RenderedLink' on their own though, lots of churn without any logic changes.
rustdoc: do not use plain summary for trait impls
Fixes#38386.
Fixes#48332.
Fixes#49430.
Fixes#62741.
Fixes#73474.
Unfortunately this is not quite ready to go because the newly-working links trigger a bunch of linkcheck failures. The failures are tough to fix because the links are resolved relative to the implementor, which could be anywhere in the module hierarchy.
(In the current docs, these links end up rendering as uninterpreted markdown syntax, so I don't think these failures are any worse than the status quo. It might be acceptable to just add them to the linkchecker whitelist.)
Ideally this could be fixed with intra-doc links ~~but it isn't working for me: I am currently investigating if it's possible to solve it this way.~~ Opened #73829.
EDIT: This is now ready!
Related to https://github.com/rust-lang/rust/issues/65354
- Pass through the replacement text to `markdown.rs`
- Add some tests
- Add a state machine that actually replaces the text when parsing Markdown
Fira Sans is what's used for module lists and other item lists.
Previously, the default body font, "Source Serif Pro", was used for
crate lists, which didn't visually match other item lists.
The old implementation only looks at numbers at the end, but not in
other places in a name: "u8" and "u16" got sorted properly, but "u8_bla"
and "u16_bla" did not.
