Need to add instructions for using the MXChip simulator in first lab

[olivierbloch]

When going through the first lab (create IoT Hub and connect the MXChip board), user can decide to use the MXChip simulator instead of the actual device. This is due to the fac that the lab instruction send user to https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-arduino-iot-devkit-az3166-get-started to setup and connect it's MXChip device. But in this page, he can choose to work with the simulator going directly here. The simulator page comes with a default interactive tutorial that instruct user to redeploy a full IoT solution with an IoT Hub, Storage and Function.
It'd be great to mention in the lab instructions that user can user the simulator and simply create a new device ID and pasting it in the simulator web page.