offenekommune startpage

*This is a pull request for the geo branch*

This fixes some issues with the offenekommune startpage and an updated theme. It seems like the respective css rules are not used anywhere else.

As I do not have a local geo installation I was not able to test this. However I applied the changes on the staging server:
https://offenekommune.staging.adhocracy.cc/

These change are no permanent solutions but should work for the moment