Project Architecture Documentation Improvements

The Dapr project thoroughly documents the architecture and design from an application developer's point of view. The Operations/SRE point of view, however, isn't clear and key information is in various places in the documentation and not in a single, easy to find location.

Recommendations:
- An overview architectural diagram/page from an Infrastructure / DevOps Architect point of view detailing:
- Infrastructure components for PoC, Dev, Test, Prod
- Infrastructure resource minimums for each environment including CPU, Network, Memory, Storage
- High Availability infrastructure components
- Observability of the project in the hosted environments themselves

xref: https://github.com/cncf/toc/issues/1354