feat: add de_formal and de_informal localizations

[psteinroe]

What kind of change does this PR introduce?

Feature

What is the current behavior?

No German translation

What is the new behavior?

Adds formal and informal translation for German.

Additional context

For non-native speakers, here is a brief explanation of formal ("Sie") and informal ("Du") translations for the English "you" in German: https://www.gymglish.com/en/wunderbla/german-grammar/du-vs-sie

[psteinroe]

@thorwebdev you might be a good reviewer here 😄

[riipandi]

Love it! This is a good idea to separate two kinds of language.