add article back to TOC

Author: vhorne

articles/application-gateway/toc.yml

@@ -71,6 +71,8 @@
       href: create-ssl-portal.md
     - name: SSL termination using Azure PowerShell
       href: tutorial-ssl-powershell.md
+    - name: End-to-end SSL termination using Azure PowerShell
+      href: application-gateway-end-to-end-ssl-powershell.md
     - name: Renew certificates
       href: renew-certificates.md
     - name: Configure SSL policy