Add configuration to lint missing docs of `pub(crate)` items
Fixes this: https://github.com/rust-lang/rust-clippy/issues/5736#issuecomment-1412442404
TODO:
- [x] Needs docs
- [x] Needs better names
- [x] Should `pub` items be checked to when this new option is enabled? I'm saying no because `missing_docs` already exists
`@flip1995` I'd like to get some input from you :)
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changelog: Enhancement: [`missing_docs_in_private_items`]: Added new configuration `missing-docs-in-crate-items` to lint on items visible within the current crate. For example, `pub(crate)` items.
[#10303](https://github.com/rust-lang/rust-clippy/pull/10303)
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