Missing function added

Author: rishiilangomaran

articles/azure-app-configuration/quickstart-feature-flag-aspnet-core.md

@@ -125,7 +125,8 @@ Add the [Secret Manager tool](https://docs.microsoft.com/aspnet/core/security/ap
             .ConfigureAppConfiguration((hostingContext, config) =>
             {
                 var settings = config.Build();
-                config.AddAzureAppConfiguration(settings["ConnectionStrings:AppConfig"]);
+                config.AddAzureAppConfiguration(settings["ConnectionStrings:AppConfig"])
+                    .UseFeatureFlags();;
             })
             .UseStartup<Startup>();
     ```
@@ -139,7 +140,8 @@ Add the [Secret Manager tool](https://docs.microsoft.com/aspnet/core/security/ap
         webBuilder.ConfigureAppConfiguration((hostingContext, config) =>
         {
             var settings = config.Build();
-            config.AddAzureAppConfiguration(settings["ConnectionStrings:AppConfig"]);
+            config.AddAzureAppConfiguration(settings["ConnectionStrings:AppConfig"])
+                .UseFeatureFlags();;
         })
         .UseStartup<Startup>());
     ```