Generate links to definition in rustdoc source code pages

[alice-i-cecile]

How can Bevy's documentation be improved?

rust-lang/rust#84176 (just merged) allows rustdoc to generate links to definitions in source code pages. This new feature is disabled by default. Once this moves off nightly we should enable the feature with the --generate-link-to-definition option.

[mockersf]

Doesn't this need to be enabled by the one building the docs which is not us but docs.rs?

The doc built during CI are not published anywhere, having the links there wouldn't be visible

[bjorn3]

docs.rs uses nightly rustdoc. It also allows you to pass arbitrary flags to rustdoc using a section in Cargo.toml I believe.

[mockersf]

https://docs.rs/about/metadata

[BD103]

Marking this as unblocked. We now use nightly to build our docs, and so does docs.rs.

[NthTensor]

Closing as fixed.