[DE] Translate docs

[yue-dongchen]

With appropriate borrowings from the French docs that are not present in the English:

• pour être parfaitement lisibles — und lässt sich damit fehlerfrei anzeigen
• images vectorielles — Vektorgrafiken (instead of “SVG”)

Reformulate the disambiguation feature description in terms of “lemma” — less cumbersome wording.

[BoboTiG]

Thanks @yue-dongchen 🥂

@all-contributors please add @yue-dongchen for translation

[allcontributors[bot]]

@BoboTiG

I've put up a pull request to add @yue-dongchen! :tada: