[CN-1194] Update warning on expose externally in Istio setup (#208)

* add warning

* update to important label

* update istio warning

* replace the warning

* fix warning

* make it note

docs/modules/ROOT/pages/connect-outside-kubernetes.adoc

@@ -39,9 +39,9 @@ If you use AKS, consider the following:
 
 == Configuring `exposeExternally`
 
-To allow connections from clients, you need to configure the `exposeExternally` field, of the Hazelcast custom resource. 
+To allow connections from clients, you need to configure the `exposeExternally` field, of the Hazelcast custom resource.
 
-IMPORTANT: If using Istio, you cannot use `exposeExternally`.
+NOTE: If using Istio, you cannot use `exposeExternally`.
 
 This field has the following properties: