README: Add anchors for rules and config options

[jtojnar]

This will allow us to link to them directly.

Using the syntax from https://sublime-and-sphinx-guide.readthedocs.io/en/latest/references.html#use-a-custom-anchor

Example: https://github.com/jtojnar/flake8-bugbear/tree/readme-anchors#user-content-b950

[jtojnar]

We may also want to add a link to name so that users can obtain it without having to dig through the source code.

[cooperlees]

Thanks for this. This would be useful, I can see.

Is there any way we can make rstcheck happy here?

• Seems it's a known problem: rstcheck/rstcheck-core#4

Can we look at adding the correct --ignore-directives to the pre-commit config please to not error rstcheck since this is a known problem.

[cooperlees]

Going to merge and fix the linting locally