changes required in future nightlies

[QuietMisdreavus]

The following PRs add new files to the rustdoc distribution:

• Add source file sidebar rust#55707 (merged, in nightly) added source-script.js as a new static file, and source-files.js as a new per-doc-bundle file. (added in add new static files from recent rustdoc changes #274)
• [rustdoc] Specific crate search rust#56332 (merged, but not in nightly yet) added down-arrow.svg as a new static file. (added in add new static files from recent rustdoc changes #274)

When both of these are in nightly (may take a while for the latter one), we'll need to update docs.rs to make sure it adds these files to the site-wide cache.

[QuietMisdreavus]

Once rust-lang/rust#56577 lands, we'll want to start passing --generate-redirect-pages to rustdoc.

[QuietMisdreavus]

rust-lang/rust#56005 adds a new static file: noscript.css. (added in #281)

[QuietMisdreavus]

I'm reopening this to keep as a running list of "changes necessary in new nightlies", especially since the last two weren't included in #274.

[QuietMisdreavus]

• After rustdoc: add new CLI flag to load static files from a different location rust#57011 merges, we can start passing --static-root-path / to rustdoc to adjust how CSS/JS files are loaded on documentation pages and increase browser cache usage. (added in updates to handle new nightlies #281)
• After Add no-crate filter option on rustdoc rust#57006 merges, we can start passing --disable-per-crate-search to disable the crate filter on the in-doc search box, which is useless for docs.rs anyway because of how it generates docs. (added in updates to handle new nightlies #281)

[QuietMisdreavus]

rust-lang/rust#57400 changes the font files distributed/used by rustdoc. Since docs.rs loads these as "essential files" but doesn't apply a resource suffix, this may be problematic, but i think we can just get away with keeping the old font files in the database and loading in the new ones when we get them. (added in #290)

[QuietMisdreavus]

rust-lang/rust#57552 adds two new static files: favicon.ico and rust-logo.png. Since docs.rs uses its own favicon, that one can technically be ignored, but new pages will start trying to reference the logo image. (added in #290)

[QuietMisdreavus]

rust-lang/rust#59776 adds the resource suffix to the per-crate files (search index, source file list, etc). We currently hardcode those files into our route listing, so we'll need to make sure to handle those when that lands. (#329)

[jyn514]

Closing this since it hasn't been used in a while and I'd rather track these in separate issues.