Take inspiration from Pandoc's Markdown

[nimobeeren]

Pandoc's Markdown has some nice things that we don't, like:

• Tables with column alignment based on spaces in the header row
• Raw LaTeX (I think this might be preferrable to our :cite[] and :ref[] syntax, and better than $$\begin{}...\end{}$$)
• They also have another syntax for citations, not sure if I like it better than raw LaTeX \cite{} but would be nice to consolidate. Note also citation prefix, locator, and suffix.
• Implicit figures, but only when the image is the only thing in the block! (seems nicer than our way of making you fall back to HTML <img> tags
• Link attributes, this could be nice for custom styling using classes, for example.
• Header attributes and generic attributes could replace the :id[] syntax.
• Curly quotes, en- and em-dash, ellipsis, non-breaking spaces