Overall project and architectual documentation

Looking at the german corona-warn app efforts and [this set of documentations ](https://github.com/corona-warn-app/cwa-documentation) I'm wondering if you plan of releasing something similar for the austrian app/system. Looking at the documentation of the german system makes me more likely to use such an app compared to what is available for the austrian system.

Start by reviewing the linked German corona-warn-app documentation and compare its coverage with what is available for the Austrian app/system. Clarify the intended scope and audience for an Austrian equivalent, then publish overall project and architectural documentation when the required coverage is agreed.

Written by the indexing model from the issue text.