Document the relation about quarkus beans and camel components

[lburgazzoli]

It is not clear what is the recommended way to use some camel components, i.e. for some messaging related components we can re-use the beans provided by quarkus thus we can leverage the build time optimization such beans can have but it is not clear how / when this applies

Relates to #1128

[ppalaga]

There is a brief Configuration by convention section now: https://camel.apache.org/camel-quarkus/latest/user-guide/configuration.html#_configuration_by_convention
But how that applies to the individual components should be documented on the individual extension/component pages.

[ppalaga]

I think this is documented sufficiently. @lburgazzoli please feel free to reopen if you disagree.