[Documentation]: Blockchain architecture

[samricotta]

Summary

https://docs.cosmos.network/main/learn/intro/sdk-app-architecture - this is out of date not only with diagrams but the bottom section on comet and ABCI - This should be the most up to date, for example this should refer to ABCI 2.0 and link to comet v.38. Again I think with anytime we speak about these abci functions we needs to be explicit around which ones are called by comet and which ones by the sdk internally.