Remove rst- prefix on CSS classes generated from docutils (all CSS classes in docstrings basically)

[tristanlatr]

This is a behaviour inherited from epydoc that we don't need I think.

And it adds extra complexity to the starttag() method of the HTMLTranslator:

pydoctor/pydoctor/node2stan.py

Line 125 in bd7bf99

def starttag(self, node: nodes.Node, tagname: str, suffix: str = '\n', **attributes: Any) -> str:

We don't need it and it makes thing more complicated where it doesn't have to be.

[tristanlatr]

This will have as effect to break all custom CSS using the older CSS class names starting by rst-. So I'de suggest we make it clear in the changelog.

[adiroiban]

Yes. Thanks for the headup.
It's important to have this in the changelog.

I don't know how many users have custom CSS. If it's just for twisted, that is ok.

[tristanlatr]

The more I think about this issue the more I believe it should be marked as won’t fix. It’s been like that from the beginning and I don’t have another reason to change that appart « I don’t think we need it ».

I’ll try to run some performance tests to see if that would improve pydoctor… but I really doubt it will be significant.