Automatic Night mode support

[abhay222]

Hey, I am using this app for long time and love using it. Can we add support for the Night mode based on the system setting.
Like if system have Dark mode selected then keyboard also show Dark mode else normal mode.

[joicemjoseph]

if you are not aware, we moved development to gitlab. If you can send future updates/issues there, that'll also be helpful - https://gitlab.com/indicproject/indic-keyboard/