update readme

README.md

@@ -35,3 +35,28 @@ ROS1 is considered end of life. It's recomended to use a ROS2 template instead
  * ROS2 template
 
 We're working on it...
+
+
+## Single Vehicle Simulation
+
+Ensure .env `SIM_DRONE_COUNT` is 1. 
+
+ 1. `docker compose --profile uav-sim --profiule ui up`
+ 2. Click `Launch Gazebo` on the menu.
+
+## Multi vehicle Simulation
+
+Ensure variables in the `.env` file are correct. 
+
+### First Terminal
+
+ 1. `docker compose --profile ui up`
+ 2. Click `Launch Gazebo` on the menu.
+
+### Second Terminal 
+
+This will launch ardupilot, mavproxy and mavros sessions, and will scale by the `SIM_DRONE_COUNT` env variable.
+
+ 1. `python3 sim_drone.py`
+
+