Adding K8s style warnings

Author: DCtheGeek

articles/governance/policy/concepts/policy-for-kubernetes.md

@@ -1,6 +1,6 @@
 ---
-title: Learn Azure Policy for Kubernetes
-description: Learn how Azure Policy uses Rego and Open Policy Agent to manage clusters running Kubernetes in Azure or on-premises.
+title: Preview - Learn Azure Policy for Kubernetes
+description: Learn how Azure Policy uses Rego and Open Policy Agent to manage clusters running Kubernetes in Azure or on-premises. This is a preview feature.
 ms.date: 05/20/2020
 ms.topic: conceptual
 ---
@@ -56,6 +56,12 @@ must enable the **Microsoft.ContainerService** and **Microsoft.PolicyInsights**
 
 1. Register the resource providers and preview features.
 
+   > [!CAUTION]
+   > When you register a feature on a subscription, you can't un-register that feature. After you
+   > enable some preview features, defaults may be used for all AKS clusters then created in the
+   > subscription. Don't enable preview features on production subscriptions. Use a separate
+   > subscription to test preview features and gather feedback.
+
    - Azure portal:
 
      1. Register the **Microsoft.ContainerService** and **Microsoft.PolicyInsights** resource

articles/governance/policy/toc.yml

@@ -77,7 +77,7 @@
   - name: Design Policy as Code workflows
     displayName: devops, infrastructure as code, iac, release, continuous, delivery, deploy
     href: ./concepts/policy-as-code.md
-  - name: Azure Policy for Kubernetes
+  - name: Azure Policy for Kubernetes (preview)
     displayName: aks, engine, k8s, rego, opa, open policy agent, gatekeeper, v3, crd, constraints, arc
     href: ./concepts/policy-for-kubernetes.md
   - name: Audit VMs with Guest Configuration