medschool: generate config field headings automatically

[t4lz]

Currently, in order to create the the headings (with anchor links) of configuration fields, e.g:

We need to write that heading in the Rust documentation, e.g: https://github.com/metalbear-co/mirrord/blob/56da9828ad2553e6c5a11124c5d65f4d4b00e6e6/mirrord/config/src/lib.rs#L181

Which is redundant, because we write the name of the field in a comment above the field, and it also leads to weird Rust docs with that same redundancy and weird item id:

I think medschool should derive the heading and anchor link without us writing it in the Rust docs.

[infiniteregrets]

I can take this one!

[eyalb181]

Thanks!