Document or error out when setup is called after enable!

[dorner]

Is your feature request related to a problem? Please describe.

I used setup to change the topic names for my app. Calling karafka-web install would fail because the deserializer was being set to the wrong topic name and it didn't symbolize the keys.

Describe the solution you'd like

Either:

• A note in the documentation to only call setup before enable!, or
• Change the behavior so setup fails with an error if called after enable!

Describe alternatives you've considered

See above :)