[DE] Add german translation for cover_HassSetPosition

[scharrrfi]

Hi all,

the german translation for HassSetPosition for cover entities is missing. When I try to set my covers to an Position, it cannot controle locally. Only my LLM can set the position.

Possible commands:
Hey Nabu, Rollladen (Raumname) auf 10 Prozent.
Hey Nabu, stelle Rollladen (Raumname) auf 10 Prozent
Hey Nabu, Position von Rollladen (Raumname) auf 10 Prozent.

Thank you for adding it.