Rewrite German translation

[felix-d1strict]

This is a complete rewrite of the German translation. Some texts have been added that have not been translated at all before, but also many have been edited. The reason for this is that the texts were also in German before, but in a German that I as a native speaker would not use like that when describing something. That's my opinion, anyway. ☺️

If I have made a spelling mistake, please give me feedback here.

Thank you very much, Felix