Update README_CN.md

Author: hejianxin79

README_CN.md

@@ -14,7 +14,10 @@ LinkerHand Python SDK
 - download
 
   ```bash
-  git clone https://github.com/linkerbotai/linker_hand_python_sdk.git
+  # 开启CAN端口
+  $ sudo /usr/sbin/ip link set can0 up type can bitrate 1000000 #USB转CAN设备蓝色灯常亮状态
+  
+  $ git clone https://github.com/linkerbotai/linker_hand_python_sdk.git
   ```
 
 - install
@@ -93,3 +96,4 @@ MODBUS: "None" or "RML"
 
 
 
+