OCPBUGS#9375: Add generic ephemeral volumes

Author: xenolinux

modules/security-context-constraints-about.adoc

@@ -330,6 +330,7 @@ sources that are defined when creating a volume:
 * link:https://kubernetes.io/docs/concepts/storage/volumes/#flexvolume[`flexVolume`]
 * link:https://kubernetes.io/docs/concepts/storage/volumes/#flocker[`flocker`]
 * link:https://kubernetes.io/docs/concepts/storage/volumes/#gcepersistentdisk[`gcePersistentDisk`]
+* link:https://kubernetes.io/docs/concepts/storage/ephemeral-volumes/#generic-ephemeral-volumes[`ephemeral`]
 * link:https://kubernetes.io/docs/concepts/storage/volumes/#gitrepo[`gitRepo`]
 * link:https://kubernetes.io/docs/concepts/storage/volumes/#glusterfs[`glusterfs`]
 * link:https://kubernetes.io/docs/concepts/storage/volumes/#hostpath[`hostPath`]