Coincidentally, just a few days ago I was also researching the possibility of Markdown editing on classic machines, because it's become my own format of choice for most writing tasks that I do. Since I've been diving more into Amiga software development lately, I might be interested in eventually taking this on as a project. It seems to be a noticeable gap in the capabilities of older systems (of all platforms), but one that's actually lightweight enough for them to comfortably handle.