Fix typos

[oliveredget]

Fix some typos in comment and docs.

[rustbot]

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[rustbot]

The rustc-dev-guide subtree was changed. If this PR only touches the dev guide consider submitting a PR directly to rust-lang/rustc-dev-guide otherwise thank you for updating the dev guide with your changes.

cc @BoxyUwU, @jieyouxu, @Kobzol

rustdoc-json-types is a public (although nightly-only) API. If possible, consider changing src/librustdoc/json/conversions.rs; otherwise, make sure you bump the FORMAT_VERSION constant.

cc @CraftSpider, @aDotInTheVoid, @Enselic, @obi1kenobi

[bjorn3]

We've seen a wave of tiny fix PRs similar to yours that we suspect are linked with blockchain rewards. To avoid encouraging this we will not accept such PRs. If you would like to contribute to the project, you are more than welcome to contribute something more substantial