Whoops, should have noticed your endorsement of syncthing before posting a comment mentioning this.
While Obsidian does save to individual files, the Markdown they use seems to be a superset of everyday Markdown. Eg, being able to use callouts (eg, Note, Warning, Info, etc) and embedded linking of notes.
The automatic backlinks are fantastic. And I’ve discovered that if I rename a note, all links to that note get updated as well. So no need to worry about orphaning pages.
I’ve added a handful of plugins as well. Off the top of my head, one is a dynamic table of contents (for that page), another helps to compose/edit Markdown tables.
Let’s not be hasty.
Surely free-range, organic, gluten-free sand would be the bestest source material ever.