add refernce card

Author: vhorne

articles/firewall/index.yml

@@ -131,3 +131,15 @@ landingContent:
         links:
          - text: Azure network security
            url: ../networking/security/index.yml
+
+  # Card
+  - title: Reference
+    linkLists:
+      - linkListType: reference
+        links:
+          - text: Azure CLI
+            url: //cli/azure/network/firewall
+          - text: Azure PowerShell
+            url: /powershell/module/az.network/new-azfirewall
+          - text: REST
+            url: /rest/api/firewal