Update de.json

[xchs]

Fixed some typos.

[aschempp]

Translations are managed on transifex.com, could you fix them there or should I adopt them?

[xchs]

@aschempp Yes, of course, I can also do this on Transifex. I have just submitted a request to join the team.

[aschempp]

Sorry about that, I just realized german is only translated by the Core team. I have adopted all your changes (except the neuste/neueste. We've discussed this at some point, and both versions are correct).

[xchs]

Thank you very much 👍🏻