[APIM] Added API ref links to ToC

Author: dlepow

articles/api-management/TOC.yml

@@ -361,6 +361,10 @@
         href: /rest/api/apimanagement/
       - name: REST (original)
         href: /rest/api/apimanagement/ApiManagementREST/api-management-REST
+      - name: .NET
+        href: /dotnet/api/overview/azure/apimanagement
+      - name: Node.js
+        href: javascript/api/overview/azure/apimanagement
       - name: Resource Manager template
         href: /azure/templates/microsoft.apimanagement/allversions
       - name: Azure Policy built-ins