Enhance API interface description with OpenAPI/Swagger/xyz format

[hb-tpfister]

In addition to your existing documentation it would be nice if you could provide the API interface descriptions in a standard format like OpenAPI / Swagger (or if you are using something else internally already, that). Benefits include a quick overview with technical details, possibilities to use client generators (which may need minor adjustments), etc.

This would either be possible via this repository or if you prefer as a living documentation on a new API endpoint of yours.

Thanks for considering!