Update api-specification-kubernetes.md

Author: cynthn

articles/application-gateway/for-containers/api-specification-kubernetes.md

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