convert-policy.py and Markdown

[annevk]

• The only affect of from mdx_partial_gfm import PartialGithubFlavoredMarkdownExtension appears to be the auto-linking of the email address in the Code of Conduct. We could consider replacing it with something simpler that handles email addresses.
• Adopting commonmark would require some restructuring of the code as it doesn't like some of the pre-processing we do. It ends up wrapping our headings with paragraphs and also encodes a bunch of " as ".

It's not clear that making either is worth it.

[domenic]

I think Commonmark is worth a lot just in being the same as GitHub and helping the Markdown ecosystem converge toward a single spec.

[annevk]

Could it be that the Python commonmark package is wrong? https://spec.commonmark.org/ behaves very similar to the markdown package we are using, especially for input such as

<h3>...</h3>
test

or

<h3>...</h3>

test

whereas if I try that locally with the commonmark package the <h3> ends up wrapped in a <p>.

[domenic]

That could be possible, if distressing :(. Although as I noted in whatwg/sg#92 (comment) I'm unsure why our input contains <h3>s anyway, instead of ###.

[annevk]

That's what convert-policy does. We could possibly change it to do post-HTML-conversion changes. That would also fix #145. But I don't think I've really seen where commonmark and markdown give different results yet. Other than that commonmark didn't do email address auto-linking. (Perhaps it needs to be wrapped inside angle brackets.)