fix(chapt3): 修复自定义接口命令错误

docs/humble/chapt3/get_started/9.自定义接口RCLPY实战.md

@@ -12,7 +12,7 @@
 ```sherll
 cd chapt3_ws/
 ros2 pkg create example_interfaces_rclpy --build-type ament_python --dependencies rclpy example_ros2_interfaces --destination-directory src --node-name example_interfaces_robot_02 --maintainer-name "fishros" --maintainer-email "fishros@foxmail.com"
-touch src/example_interfaces_rclpy/src/example_interfaces_control_02.py
+touch src/example_interfaces_rclpy/example_interfaces_rclpy/example_interfaces_control_02.py
 ```
 
 setup.py