Always provide English name for term in translations

[alxlo]

When working with the German translation my students mentioned that it would be super helpful, to always have the original Englisch name for the term at hand. E.g.

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Entwurfsprinzip (Design Principle)

Eine Reihe von Richtlinien, die Softwareentwicklern hilft, bessere ...

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This could be an optional feature, so we can generate an additional variant/flavour of each non-English versions of the glossary. There could even be links to the English glossary entry, see #57

However, for some terms this is already manually provided, so we should have to check those.