added output of app ip

Author: TomArcherMsft

quickstart/201-k8s-cluster-with-aks-applicationgateway-ingress/output.tf

@@ -33,4 +33,8 @@ output "identity_resource_id" {
 
 output "identity_client_id" {
     value = azurerm_user_assigned_identity.testIdentity.client_id
-}
+}
+
+output "application_ip_address" {
+    value = azurerm_public_ip.test.ip_address
+}