BZ#2092710: Addling link to image registry config for Cinder volumes

Author: skrthomas

installing/installing_openstack/installing-openstack-installer-custom.adoc

@@ -22,6 +22,7 @@ include::modules/installation-osp-control-compute-machines.adoc[leveloffset=+2]
 include::modules/installation-osp-bootstrap-machine.adoc[leveloffset=+2]
 include::modules/cluster-entitlements.adoc[leveloffset=+1]
 include::modules/installation-osp-enabling-swift.adoc[leveloffset=+1]
+include::modules/installation-registry-osp-creating-custom-pvc.adoc[leveloffset=+1]
 include::modules/installation-osp-verifying-external-network.adoc[leveloffset=+1]
 include::modules/installation-osp-describing-cloud-parameters.adoc[leveloffset=+1]
 include::modules/installation-osp-setting-cloud-provider-options.adoc[leveloffset=+1]