Update de.json

Fixed typos, added notes.
(It is a bit difficult to see the typos in the GitHub online editor ;) )

I already translated the donate-content, but it is not shown on the page. There is just the title German, the rest stays English.
Update de.json

Typo fix, added notes
Update de.json

Renamed " "i18n-self-hosting-title" to "i18n-hardware-software".

I am not very familiar with GitHub yet, so sorry for the huge amount of commits.
Merge pull request #494 from Casimo/patch-3

de.json fix