Added strings.xml for de

[SmartDever02]

[DebugBoard]

Two obvious notes on the German strings.

That said, looking at the wave of MRs (#409 - #424) this smells a lot like an LLM was involved. The lack of declaration/transparency concerns me. So I would be careful to take these MRs without human review by a native speaker :/

Had just messaged Simon about this, I don't know if it's safe to merge these as we can't verify them.

[simondankelmann]

Yes, propably it makes Sense to have them checked one by one. Ideally by native speakers