OADP-6539: Document Netapp ontap s3 as fully supported

Signed-off-by: A.Arnold <anarnold@redhat.com>

Author: anarnold97

modules/oadp-s3-compatible-backup-storage-providers.adoc

@@ -21,6 +21,7 @@ The following AWS S3 compatible object storage providers are fully supported by
 * Ceph RADOS Gateway (Ceph Object Gateway)
 * Red Hat Container Storage
 * {odf-full}
+* NetApp ONTAP S3 Object Storage
 
 [NOTE]
 ====