Link from Policies concept to NetworkPolicy page

Author: Tim Bannister

content/en/docs/concepts/policy/_index.md

@@ -4,3 +4,8 @@ weight: 90
 description: >
   Policies you can configure that apply to groups of resources.
 ---
+
+{{< note >}}
+See [Network Policies](/docs/concepts/services-networking/network-policies/)
+for documentation about NetworkPolicy in Kubernetes.
+{{< /note >}}