Yet another Vault-Tec watch face!

It's pretty straightforward, but has a few options:
- Battery is indicated as "OK", "BATT LOW" or "BATT CRIT". Thresholds for LOW and CRIT are configurable.
- No options for vibrating on Bluetooth disconnect, but the watch face will display "OFFLINE" when disconnected. You can optionally turn this off if you don't want it.