In preparation for our handover, we want to make sure that all documentation is in perfect shape.
This ticket to a make space and reserve some extra time to keep documentation up to date.

Questions to ask yourself:
Is the documentation up to date with the currently deployed version of Phonos?
Is the documentation appropriate for the reader addressed?
Is there documentation about how to extend the functionality of Phonos again, when another team or volunteer wants to make Phonos work with a TTS engine?
Has the current data tracking, currently implemented, been documented? (preferrably dev docs) What is being tracked and how does one add to it?