Notes should be exportable

This came up while I was playing around with Thunk Notes. It's really important for me for my notes to be exportable. It doesn't even have to be completely open source, but there should at least be a way for me to paste notes out of the app I'm currently in and put them in another app.

Having notes be Markdown, even in kind of a weird Markdown format like The Archive, is so much better than having notes either be locked in or in a weird format to export.