Make /about/contact translatable

While creating /about/contact in #7698 (closed) we forgot to make it translatable. Most of it is only for contributors (and /contribute is not translated) but not all of it and this is specified on this page, so this information about languages should be translated.

Feature Branch: web/11424-translate-about-contact

Related issues

Related to #7698 (closed)
Related to #11512 (closed)
Blocks #11423

Original created by @sajolida on 11424 (Redmine)

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