Create documentation (generated) on how to use the AMT application and how it is architectured

For external users it is useful to have documentation on how the AMT software can be run and used.

Create/enable Swagger or OpenAPI document
Expand/update/add docstring
Update and host a page with a mermaid architecture diagram (currently here: https://github.com/MinBZK/amt/tree/main/docs/architecture), mark with color what is currently realized and what's not yet.
host on /docs/api and /docs/architecture in amt

MinBZK / amt