Hot take (maybe): GitHub flavored markdown is the ideal markup language. If the author’s ideas were actually better, we’d use them instead.

It supports code well, it supports non-enumerated lists well, it supports enumerated lists well (if you don’t want view it in rendered markdown, you can view the raw and just disregard the numbers, understanding that the items are supposed to be sequential). It supports links well. It supports images well. It’s easily readable, even with no prior context (@toml, yaml, etc.).

It does whatever a static website could want, and it does it all decently well.