Notes for implementer not visible on docs.rs

[JuliDi]

The "notes for implementers" in the async version's udp.rs

https://github.com/rust-embedded-community/embedded-nal/blob/2ad0b03083c250b61c0b8f8ef36f3063391175dc/embedded-nal-async/src/stack/udp.rs#L1-L15

do not appear on docs.rs as from what I see.

If you let me know where it is supposed to appear, I could try fixing it and make a PR. Supposedly it should appear at the top of each trait's page, i.e., be moved below this line: https://github.com/rust-embedded-community/embedded-nal/blob/2ad0b03083c250b61c0b8f8ef36f3063391175dc/embedded-nal-async/src/stack/udp.rs#L28