I just started messing around as part of looking for a way to make contributing to tutorials easier, and got as far as using 'ssg5', from https://rgz.ee/ssg.html, which was recommended as a markdown-converting static site generator on another board here.
I had problems with Markdown.pl not working but I posted to REQUESTS, and they added it.
Because I didn't like how it silently would fail on the markdown problem, I added a little pipeline-tracing with the bash 'caller' command (I looked it up), and so with that it becomes a bash script instead of a plain sh script, but I think it's better. I posted it here on the sdf git if anyone wants to try it out.
It's cool, it processes markdown first then HTML, so existing HTML files are untouched until you delete them from src folder.