Update toc.yml

Author: eshashah-msft

articles/iot-hub-device-update/toc.yml

@@ -28,6 +28,8 @@ items:
       href: device-update-control-access.md
     - name: Device Update limits
       href: device-update-limits.md
+    - name: Monitor Device Update for IoT Hub
+      href: monitor-device-update-iot-hub.md
   - name: Devices 
     items:
     - name: Device Update agent