Re-map the Caps Lock Key to Esc on Mac

Seil is a very cool utility for key re-mapping / enabling international keys on a Mac. I wanted to re-map the mostly useless Caps Lock key to Esc, which I use constantly in vi. If you’re a regular vi user, you know exactly what I’m talking about. Now I just have to develop the muscle memory to start using it regularly instead of reaching way up for the usual Esc key.