Add support for paradoxGroups

[magro]

Thanks for this nice theme!

I tried it together with defined paradoxGroups, and the dropdown for this is not aligned correctly:

[jonas]

There's not currently any support for paradoxGroups in the theme. This will require both CSS to align elements and JavaScript to switch based on selection (basically embedding the code from Paradox's generic theme).

[magro]

Ok, I wasn't aware of this.