add how to use in readme

README.md

@@ -11,4 +11,21 @@ Several ros2 packages are list:
 | harvest_arm_rm | The driver package for the arm (take the realman-rm75 for an example). Receive joint command, and feedback arm state. | __IN__: /action/arm, the command including enable, target joint, and tool.  __Out__: /Observation/arm, the state of the robot, including measured arm joint positions, joint speed, timer counter, etc. |
 | harvest_arm_ctrl | The kinematic part of the arm, containing forward/inverse kinematics. Transformation from pose to joint. The security regulations/constraints are deployed. | - |
 | harvest_arm_retarget | Transformation among different frames. Convert target into robot arm frame. | - |
-------------------------------------------------------------------
+------------------------------------------------------------------
+
+### Build
+
+```
+mkdir -p ~/harvest_arm_ws/src  
+cd ~/harvest_arm_ws/src
+git clone https://git.nicecart.ai/ZhengLiu-cart/HarvestingRealman.git
+cd ~/harvest_arm_ws
+colcon build --symlink-install
+```
+
+### Run
+`ros2 launch harvest_arm_rm rm_arm_rviz.launch.py`
+
+
+
+