[zh] sync docs/concepts/policy/_index.md

Signed-off-by: xin.li <[email protected]>

Author: my-git9

content/zh-cn/docs/concepts/policy/_index.md

@@ -3,3 +3,19 @@ title: "策略"
 weight: 90
 description: 可配置的、可应用到一组资源的策略。
 ---
+
+<!--
+title: "Policies"
+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.
+-->
+有关 Kubernetes 中的 NetworkPolicy 的文档，
+请参阅[网络策略](/zh-cn/docs/concepts/services-networking/network-policies/)。
+{{< /note >}}