We should add the team's recommendations for using state-only transfer to complete a migration of an application if that application is externally managed by a CD system.

See the upstream documentation marked as blocking this ticket for the content.

I believe that we want this recommendation to be documented downstream here: https://docs.openshift.com/container-platform/4.9/migration_toolkit_for_containers/advanced-migration-options-mtc.html#migration-state-migration-cli_advanced-migration-options-mtc