Update policy-overview.md

Author: cynthn

articles/web-application-firewall/ag/policy-overview.md

@@ -2,7 +2,7 @@
 title: Azure Web Application Firewall (WAF) policy overview
 description: This article is an overview of Web Application Firewall (WAF) global, per-site, and per-URI policies.
 services: web-application-firewall
-ms.topic: article
+ms.topic: concept-article
 author: winthrop28
 ms.service: azure-web-application-firewall
 ms.date: 10/06/2023