[jasonl99]

I started using (and subscribed to) Inkdrop[1] after recommendations here and have been very happy with it. Yes, it's $5 a month, but it automatically syncs (encrypted locally first), and has a way of doing full local directory backup that you could sync with github. The the editor is really nicely done (full github-flavor syntax highlighting too).

I'm using clients for Mac, Android and linux (manjaro) and all work well. There are also clients for the other major platforms.

One of the things I really like about it is I can do a screenshot on both Mac & linux, saving to the clipboard rather than a file, and paste it directly into an editor and inkdrop handles everything, including creating a file and corresponding markup. And that all syncs too.

[1] https://inkdrop.app/