Added --secret-from option to 'Restore from pgbasebackup' example (#550)

Author: andrewlecuyer

hugo/content/Operator CLI/_index.md

@@ -180,7 +180,7 @@ before you do a restore.
 
 #### Restore from pgbasebackup
 
-    pgo create cluster restoredcluster --backup-path=/somebackup/path --backup-pvc=somebackuppvc
+    pgo create cluster restoredcluster --backup-path=/somebackup/path --backup-pvc=somebackuppvc --secret-from=mycluster
 
 ### Fail-over Operations