Update faq.yml

Author: cynthn

articles/application-gateway/for-containers/faq.yml

@@ -6,7 +6,7 @@ metadata:
   author: greglin
   ms.service: azure-application-gateway
   ms.subservice: appgw-for-containers
-  ms.topic: article
+  ms.topic: concept-article
   ms.date: 02/27/2024
   ms.author: greglin