expand QS for AFD

Author: duongau

articles/frontdoor/TOC.yml

@@ -22,8 +22,10 @@
   expanded: true
   items:
   - name: Front Door
+    expanded: true
     items:
     - name: Standard/Premium
+      expanded: true
       items:
       - name: Create a Front Door - Portal
         href: create-front-door-portal.md
@@ -664,4 +666,4 @@
         href: https://stackoverflow.com/questions/tagged/azure-cdn
       - name: Videos
         href: https://azure.microsoft.com/documentation/videos/index/?services=cdn
-    
+