cleanup readme.

Author: zlj-zz

README.md

@@ -8,8 +8,6 @@ This is a python API for serial communication with mycobot and controlling it.
 
 **Notes**:
 
-<!-- This is the mycobot Python API package designed by Zhang Lijun([[email protected]]()) -->
-
 > Make sure that `Atom` is flashed into the top Atom, `Transponder` is flashed into the base Basic. <br>
 > The firmware `Atom` and `Transponder` download address: [https://github.com/elephantrobotics/myCobot/tree/main/Software](https://github.com/elephantrobotics/myCobot/tree/main/Software)<br>
 > You also can use myStudio to flash them, myStudio address: [https://github.com/elephantrobotics/myStudio/releases](https://github.com/elephantrobotics/myStudio/releases)
@@ -41,6 +39,12 @@ cd <your-path>/pymycobot
 
 ## Usage:
 
+```python
+from pymycobot.mycobot import mycobot
+from pymycobot.mycobot import Angle, Coord
+from pymycobot import PI_PORT, PI_BAUD # For raspberry pi version of mycobot.
+```
+
 The [`demo`](./demo) directory stores some test case files.
 
 You can find out which interfaces pymycobot provides in `pymycobot/README.md`.