Undocumented public item in source code RS-D1001

All language items that are publicly exposed must be documented. Providing documentation through comments or the #[doc] attribute allows other developers to conveniently understand the code and use the modules or crates appropriately.

Contrary to rustdoc, this issue is also raised on all non-private items. If an item has been marked pub, pub(crate), or pub(path), it indicates the possibility of usage outside the same module, and hence would ideally require documentation, despite not being exposed outside the crate.