Adding TOC item for JS Service Module

Adding a link to the reference documentation for the JavaScript Service Module to the TOC.

Author: chgennar-zz

articles/azure-maps/toc.yml

@@ -101,7 +101,9 @@
   - name: JavaScript
     items:
     - name: Map control
-      href: https://docs.microsoft.com/javascript/api/azure-maps-javascript/
+      href: https://docs.microsoft.com/en-us/javascript/api/azure-maps-javascript/
+    - name: Service module
+      href: https://docs.microsoft.com/en-us/javascript/api/azure-maps-rest/
 - name: Related
   items:
   - name: Solutions