Lint missing_intra_doc_link

[Veetaha]

Lint explanation

Detect references in comments of form `foo` where foo path is reachable in the current scope and thus the reference could be made into an intra-doc link. The reasoning is that references to other symbols will be highlighted and enriched with a link in the generated documentation. The intra-doc link will also be validated by rustdoc to stay valid, so this way the comment that references some paths will be guaranteed to have valid references.

Example code

Bad

/// This struct implements `crate::TraitName` in such a way that it does foo.
struct Foo;

Good

/// This struct implements [`crate::TraitName`] in such a way that it does foo.
struct Foo;