Update README.md

Author: pablogs9

README.md

@@ -26,7 +26,7 @@ Is possible to use a micro-ROS Agent just with this docker command:
 
 ```bash
 # Serial micro-ROS Agent
-docker run -it --rm -d /dev:/dev --privileged --net=host microros/micro-ros-agent:foxy serial --dev [YOUR BOARD PORT] -v6
+docker run -it --rm -v /dev:/dev --privileged --net=host microros/micro-ros-agent:foxy serial --dev [YOUR BOARD PORT] -v6
 ```
 
 ## How to build the precompiled library