Add prompt for adding untracked files!

[drobati]

If there are untracked files you currently have to use 'git add *' or something like it.

Make a bad ass interactive prompt since we have the power of react, that lets you keypress navigate and pick which files to track.

Some considerations: if there are HUNDREDS of untracked files we shouldn't show the prompt and instead prompt to continue or give the user the opportunity to quit, git add, then bb commit again