Merge pull request #52119 from bmcelvee/OSDOCS-4255

OSDOCS-4255: clarify public and private API endpoints

Author: bmcelvee

modules/rosa-sts-creating-a-cluster-with-customizations-ocm.adoc

@@ -258,6 +258,15 @@ Alternatively, you can set your autoscaling preferences for the default machine
 +
 [IMPORTANT]
 ====
+The API endpoint cannot be changed between public and private after your cluster is created.
+====
++
+Public API endpoint:: Select *Public* if you do not want to restrict access to your cluster. You can access the Kubernetes API endpoint and application routes from the internet.
+
+Private API endpoint:: Select *Private* if you want to restrict network access to to your cluster. The Kubernetes API endpoint and application routes are accessible from direct private connections only.
++
+[IMPORTANT]
+====
 If you are using private API endpoints, you cannot access your cluster until you update the network settings in your cloud provider account.
 ====