fixes

Author: asudbring

articles/vpn-gateway/TOC.yml

@@ -11,6 +11,8 @@
     href: tutorial-create-gateway-portal.md
   - name: Configure a site-to-site connection
     href: tutorial-site-to-site-portal.md
+  - name: Deploy VPN gateway with DDoS protection
+    href: tutorial-protect-vpn-gateway.md
 - name: Samples
   items:
   - name: Azure PowerShell