Add OPA Gatekeeper deprecation notice

docs/integrations-in-rancher/opa-gatekeeper.md

@@ -6,6 +6,8 @@ title: OPA Gatekeeper
   <link rel="canonical" href="https://ranchermanager.docs.rancher.com/integrations-in-rancher/opa-gatekeeper"/>
 </head>
 
+<DeprecationOPAGatekeeper link="kubewarden" />
+
 To ensure consistency and compliance, every organization needs the ability to define and enforce policies in its environment in an automated way. [OPA (Open Policy Agent)](https://www.openpolicyagent.org/) is a policy engine that facilitates policy-based control for cloud native environments. Rancher provides the ability to enable OPA Gatekeeper in Kubernetes clusters, and also installs a couple of built-in policy definitions, which are also called constraint templates.
 
 OPA provides a high-level declarative language that lets you specify policy as code and ability to extend simple APIs to offload policy decision-making.

docs/reference-guides/rancher-cluster-tools.md

@@ -41,8 +41,11 @@ For more information, refer to the monitoring documentation [here.](../integrati
 Rancher's integration with Istio was improved in Rancher v2.5.
 
 For more information, refer to the Istio documentation [here.](../integrations-in-rancher/istio/istio.md)
+
 ## OPA Gatekeeper
 
+<DeprecationOPAGatekeeper link="../integrations-in-rancher/kubewarden" />
+
 [OPA Gatekeeper](https://github.com/open-policy-agent/gatekeeper) is an open-source project that provides integration between OPA and Kubernetes to provide policy control via admission controller webhooks. For details on how to enable Gatekeeper in Rancher, refer to the [OPA Gatekeeper section.](../integrations-in-rancher/opa-gatekeeper.md)
 
 ## CIS Scans