What I really really want is a tool that keeps notes in github, therefore an open/standard/robust way to do offline, merge changes, resolve conflicts. I've los

What I really really want is a tool that keeps notes in github, therefore an open/standard/robust way to do offline, merge changes, resolve conflicts. I've lost so much data from Evernote's atrocious conflict resolution that it's my central concern. I don't see any mention of that here. Use case: edit notes on a plane on laptop, edit notes on phone after landing, sometime later use laptop again and zap.