Is there a possibility to add footnotes support? I’d be glad to have them for pages like this one.

Thanks for the feature request. Do you mean you’d like to be able to click the footnote references in the text and jump to the note? I don’t think this works at the moment because we convert all relative links into absolute links, and so the Kindle will try to load the full URL rather than jump to a part of the same document.

It’s something we should be able to support though, so hopefully we can handle these kind of links better in a future update.