Added a TOC item for real-time web apps

Author: kevinguo-ed

articles/app-service/toc.yml

@@ -329,6 +329,8 @@
           href: web-sites-traffic-manager.md
         - name: About hybrid connections
           href: app-service-hybrid-connections.md
+        - name: Real-time web apps
+          href: ../azure-web-pubsub/howto-integrate-app-service.md?toc=/azure/app-service/toc.json
     - name: Azure Policy built-ins reference
       displayName: samples, policies, definitions
       href: ./policy-reference.md