Potentially support multiple instances of jot simultaneously

[Utagai]

Right now, if you are editing one document via jot and wish to open another one jot will complain about the directory being dirty:

Error: base-dir (/home/bob/foo/bar) is not clean, please fix the issue and run jot again

This can be annoying, but it isn't clear how to approach this, since if we don't enforce this, edits for both documents will get committed. It is possible that we made the wrong design choice initially -- we shouldn't stage everything for commit, but just the file you opened with $EDITOR. The problem with this of course is that you may have added other things as well, like an image file referenced in Markdown which wouldn't be captured.