Update index.yml

added link to az aro docs

Author: bentterp

articles/openshift/index.yml

@@ -51,8 +51,10 @@ landingContent:
     linkLists:
       - linkListType: reference
         links:
-          - text: Azure CLI
+          - text: Azure CLI OpenShift 3
             url: /cli/azure/openshift
+          - text: Azure CLI OpenShift 4
+            url: /cli/azure/aro
           - text: REST API
             url: /rest/api/openshift
           - text: Red Hat OpenShift docs