Improve Middleware Docs

[picklelo]

[tlinjordet]

:+1: It would be good to be able to write custom logging messages and know how different sections of code (even different messages for different sections inside a single method would trigger these. E.g., one custom message for a try-clause and a different message for the except-clause.

[picklelo]

The whole middleware idea may need a revamp and improvement - closing this until we start that project.