Update README.md

README.md

@@ -27,6 +27,7 @@ To be able to test our code, there are a few requirements.
 * For Desktop/Laptop development, see this [section](https://github.com/SherbyRobotics/racecar/tree/ros2/images#creating-a-virtual-machine) to setup ROS in a virtual machine or in a dual boot with Ubuntu 22.04
 
 * Click here to [download the default virtual machine](https://usherbrooke-my.sharepoint.com/:u:/g/personal/lali3401_usherbrooke_ca/ET_KS0N6qFpPjCdlN4sOIrYBsIMreMN1X6O5qblisWM_Rw?e=6nY1pi), see this [section](https://github.com/SherbyRobotics/racecar/tree/ros2/images/images#importing-a-virtual-machine) for how to import it in Virtual box
+    Use the VM to show topics and view them in RVIZ to limit the usage of the RaspberryPi. You might need to change the [ROS_DOMAIN_ID](https://docs.ros.org/en/rolling/Concepts/Intermediate/About-Domain-ID.html) on both machine before using it : `export ROS_DOMAIN_ID = X`
 
 ### Documentation
 * [Hardware Connections](https://github.com/SherbyRobotics/racecar/blob/ros2/doc/README.md#hardware-connections)