Merge pull request #90762 from subhtk/osdocs12366

OSDOCS 12366: Added a step and important admonition related to release image signatures in oc-mirror v2.

Author: lpettyjo

modules/oc-mirror-updating-cluster-manifests-v2.adoc

@@ -29,6 +29,20 @@ In oc-mirror plugin v2, the IDMS and ITMS files cover the entire image set, unli
 $ oc apply -f <path_to_oc_mirror_workspace>/working-dir/cluster-resources
 ----
 
+. If you mirrored release images, apply the release image signatures to the cluster by running the following command:
++
+[source,terminal]
+----
+$ oc apply -f working-dir/cluster-resources/signature-configmap.json 
+----
++
+[IMPORTANT]
+====
+If you are mirroring Operators instead of clusters, do not run the preceding command. Running the command results in an error because there are no release image signatures to apply.
+
+Additionally, a YAML file is available in the same directory `working-dir/cluster-resources/`. You can use either the JSON or YAML format.
+====
+
 .Verification
 
 . Verify that the `ImageDigestMirrorSet` resources are successfully installed by running the following command: