Added TOC entry

Author: Michael Bender

articles/virtual-network-manager/TOC.yml

@@ -115,10 +115,14 @@
       href: how-to-view-applied-configurations.md
     - name: Define dynamic network group membership with Azure Policy
       href: how-to-define-network-group-membership-azure-policy.md
-    - name: Create user-defined routes (UDRs)
-      href: how-to-create-user-defined-route.md
     - name: Common issues
       href: common-issues.md
+  - name: User-defined routes (UDRs) management
+    items:
+    - name: Create user-defined routes (UDRs)
+      href: how-to-create-user-defined-route.md
+    - name: deploy hub and spoke topology with Azure Firewall
+      href: how-to-deploy-hub-spoke-topology-with-azure-firewall.md
 - name: Reference
   items:
   - name: Code samples