Fixes#14628
- Remove mdbook-linkcheck dependency and configuration (was blocking
upgrades to mdbook 0.5.0+, configured with warning-policy = "ignore"
due to false positives, and redundant with lychee-based link checking)
- Update substitute.py and anchors.jq to handle 'items' (mdbook 0.5.x)
in addition to 'sections' (mdbook 0.4.x), as per mdbook 0.5.0
changelog: "Book::sections was renamed to Book::items"
https://github.com/rust-lang/mdBook/blob/master/CHANGELOG.md#05-migration-guide
(cherry picked from commit 2636f50dd4)
This renders the rl-next notes when `officialRelease = false`, which
corresponds to the case where we're not on a release branch.
Previously we had disabled this behavior because changelog-d is
somewhat of a heavy dependency, being the only Haskell package.
However, we now have new circumstances that topple the tradeoff.
- We render `master` docs to https://nix.dev/manual/nix/development/release-notes/rl-next.html
- `.#manual` is a separate build now, so `nix build nix/foo` is
not affected by the increased closure of build input outputs.
Because of these factors, I believe adding this functionality back
is more valuable, as we can use it to
- Previous release notes
- Showcase the upcoming release to the community
