Add missing German translation (#3183)
Add missing German translation (#3183)

* Add missing German translation

* Replace whitespace in text with underscore

* Bibtex format and Numerals -> Zifferns

tobiasdiez/jabref,Siedlerchr/jabref,zellerdev/jabref,zellerdev/jabref,JabRef/jabref,sauliusg/jabref,oscargus/jabref,oscargus/jabref,tobiasdiez/jabref,JabRef/jabref,JabRef/jabref,shitikanth/jabref,sauliusg/jabref,tobiasdiez/jabref,Siedlerchr/jabref,sauliusg/jabref,shitikanth/jabref,oscargus/jabref,zellerdev/jabref,JabRef/jabref,shitikanth/jabref,Siedlerchr/jabref,oscargus/jabref,oscargus/jabref,shitikanth/jabref,Siedlerchr/jabref,sauliusg/jabref,tobiasdiez/jabref,shitikanth/jabref,zellerdev/jabref,zellerdev/jabref