Update docfx.json

Author: Saisang

docfx.json

@@ -49,7 +49,7 @@
       "show_latex": true,
       "uhfHeaderId": "MSDocsHeader-DotNet",
       "apiPlatform": "dotnet",
-      "ms.topic": "reference",
+      "ms.topic": "generated-reference",
       "ms.service": "dotnet-api",
       "products": ["https://authoring-docs-microsoft.poolparty.biz/devrel/7696cda6-0510-47f6-8302-71bb5d2e28cf"],
       "feedback_system": "OpenSource",