If a user chooses to setup RHDG cross-site replication with OpenShift Routes, no example documentation is provided for the Secret with the truststore needed by the Infinispan cluster

In the prerequisite section, it could also  be made clearer that the Infinispan router Pods won't start without a Secret. The Operator will not reject an Infinispan CR with `spec.service.sites.local.expose.type` Route that is missing a Secret name.

Inspiration could be taken from the AMQ doc which as both an example with manual creation with keytool or using Cert-Manager if RHDG can support the format.