Update to backgammon timer app

A while back, I posted a link to a timer I made specifically for backgammon. The idea being that an online timer would make it easier to introduce new players to match play without having to buy all the gear.

https://backgammontimer.com/

I recently added the ability to undo/redo moves in the timer, so please give it another look.

As always, if you have any feature/change requests, please let me know.