The <tt> tag is deprecated, according to:
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/tt

The <code> tag is proposed as a replacement. It has the same intented
semantics: an inline block of code:
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/code

Closes #41.

This fixes the worst parts of the German translation.

- remove 0% complete es, fr and it translations
- update fuzzy strings for de, with fixes which I am sure are safe

Adding new strings from the source files

person/templates/person/person.html
process/templates/process/explain_statement_advocate.html
process/templates/process/explain_statement_am_ok.html
process/templates/process/explain_statement_approval.html
process/templates/process/explain_statement_sc_dmup.html
process/templates/process/req_keycheck.html

Probably not a final state and an ongoing work in progress for now.

Closes: #892578