⚒️ Add a CLI tool for extracting info between two revisions

[paddycarver]

We should be able to pass in any two git refs (tag, branch, commit, etc.) and then pull all the music logged in between those two refs. This would let us have "release playlists", containing all the songs (ordered by frequency? ordered by date? ordered by both?) that developers listened to during a release.

[paddycarver]

LOL, the Spotify API would let us automate creation of these playlists :D We'd need to search for the Spotify equivalent of the Plex songs, but that seems reasonably doable.