docs: Question about messaging defaults

[mcruzdev]

Problem

I am using the quarkus-flow-messaging extension, and I enabled using the propery quarkus.flow.messaging.defaults-enabled=true.

My workflow only emit events through emitJson, there is no incoming message and I am receiving the following message error:

Caused by: jakarta.enterprise.inject.spi.DeploymentException: java.lang.IllegalArgumentException: The attribute `value.deserializer` on connector 'smallrye-kafka' (channel: flow-in) must be set                

Suggestion

It would be great in Dev mode to have that configurations provided by default if not set. Maybe the user wants to send or receive a message, not both.