Adds important note to OMR ensuring that it's not intended to be used for production purposes

Author: Steven Smith

disconnected/mirroring/installing-mirroring-creating-registry.adoc

@@ -10,6 +10,11 @@ The _mirror registry for Red Hat OpenShift_ is a small and streamlined container
 
 If you already have a container image registry, such as Red Hat Quay, you can skip this section and go straight to xref:../../disconnected/mirroring/installing-mirroring-installation-images.adoc#installation-mirror-repository_installing-mirroring-installation-images[Mirroring the OpenShift Container Platform image repository].
 
+[IMPORTANT]
+====
+The _mirror registry for Red Hat OpenShift_ is not intended to be a substitute for a production deployment of {quay}.
+====
+
 [id="prerequisites_installing-mirroring-creating-registry"]
 == Prerequisites