Setting for Gamepad Battery

[ToastedWookiee]

The setting to show gamepad_battery has been changed as referenced here, and therefore no longer works with the setting from goverlay.

flightlessmango/MangoHud#1108 (comment)

Ok just pushed a commit, it changes things a bit though.

gamepad_battery is no more now it is device_battery which takes a string.

for example device_battery=gamepad or device_battery=mouse or device_battery=gamepad,mouse for both.

[benjamimgois]

Thanks for the tip @ToastedWookiee , i'll update the code on 1.0 release that isn't upstreamed yet.