Improve wording in German texts
Description
There are suggestions to improve the style of German texts: https://hackmd.okfn.de/6BiFNRpxSrOV9Q-octTjFQ This would need to be changed in the translation files because German as the original language can't be changed in weblate.
Links / references
https://yunity.slack.com/archives/C1T1ZM9A4/p1615898197007900