add link and toc

Author: vhorne

articles/firewall/firewall-preview.md

@@ -45,7 +45,8 @@ Policy Analytics provides insights, centralized visibility, and control to Azure
 ### Explicit proxy (preview)
 
 With the Azure Firewall Explicit proxy set on the outbound path, you can configure a proxy setting on the sending application (such as a web browser) with Azure Firewall configured as the proxy. As a result, traffic from a sending application goes to the firewall's private IP address, and therefore egresses directly from the firewall without using a user defined route (UDR).
-For more information, see Azure Firewall Explicit Proxy.
+
+For more information, see [Azure Firewall Explicit proxy (preview)](explicit-proxy.md).
 
 
 ## Next steps

articles/firewall/toc.yml

@@ -107,6 +107,8 @@ items:
       href: long-running-sessions.md
     - name: Easy upgrade/downgrade
       href: easy-upgrade.md
+    - name: Explicit Proxy
+      href: explicit-proxy.md
 - name: How-to guides
   items:
     - name: Deploy and configure - classic