Merge pull request #233401 from spelluru/egridtoc0404

minor update to TOC

Author: JamesJBarnett

articles/event-grid/toc.yml

@@ -28,12 +28,14 @@ items:
         href: blob-event-quickstart-template.md
     - name: Publish and subscribe using custom topics
       items:
-      - name: Portal
-        href: custom-event-quickstart-portal.md
-      - name: Azure CLI
-        href: custom-event-quickstart.md
-      - name: PowerShell
-        href: custom-event-quickstart-powershell.md
+      - name: Custom events to Event Grid Viewer app
+        items:
+        - name: Portal
+          href: custom-event-quickstart-portal.md
+        - name: Azure CLI
+          href: custom-event-quickstart.md
+        - name: PowerShell
+          href: custom-event-quickstart-powershell.md
       - name: Custom events to an Azure function 
         href: custom-event-to-function.md
       - name: Custom events to an Azure Queue storage