German translations

[martin-raden]

Providing the translations for sandpaper tutorials in German language.

[froggleston]

Many thanks for this PR @martin-raden ! However, the file you have committed is in the root folder of the repo, when it should be in the po folder. Please could you move it, update the PR, and I can merge it in?

[martin-raden]

uaks... sorry, my fault. Didnt check the file's location after creating it.. should be fine now!

Thanks for merging (and hopefully releasing soon.. 😜🤞)

[froggleston]

All merged in and released, so thank you so much for your very first contribution @martin-raden ! 🥳

[martin-raden]

wow, many thanks for the fast release. just in time for the upcoming teaching period next week! 😄