We already have community doc for the IstioRevisionTag CRD, but we still need to add some information to the product docs. This should be added to the list of OSSM resources: https://docs.redhat.com/en/documentation/red_hat_openshift_service_mesh/3.0.0tp1/html/about/understanding-service-mesh#ossm-about-concepts-resources_ossm-about-concepts-assembly. 

Note: We have broken out related content for the sidecar injection page into this issue: https://issues.redhat.com/browse/OSSM-8954, and content for updates is part of this issue: https://issues.redhat.com/browse/OSSM-8218.