Update CONTRIBUTING.md

Author: AtsushiSakai

CONTRIBUTING.md

@@ -1,23 +1,5 @@
-# Contributing to Python
+# Contributing
 
-:+1::tada: First of off, thanks very much for taking the time to contribute! :tada::+1:
+:+1::tada: First of all, thank you very much for taking the time to contribute! :tada::+1:
 
-The following is a set of guidelines for contributing to PythonRobotics. 
-
-These are mostly guidelines, not rules. 
-
-Use your best judgment, and feel free to propose changes to this document in a pull request.
-
-# Before contributing
-
-## Taking a look at the paper.
-
-Please check this paper to understand the philosophy of this project.
-
-- [\[1808\.10703\] PythonRobotics: a Python code collection of robotics algorithms](https://arxiv.org/abs/1808.10703) ([BibTeX](https://github.com/AtsushiSakai/PythonRoboticsPaper/blob/master/python_robotics.bib))
-
-## Check your Python version.
-
-We only accept a PR for Python 3.8.x or higher.
-
-We will not accept a PR for Python 2.x.
+Please check this document for contribution: [How to contribute — PythonRobotics documentation](https://atsushisakai.github.io/PythonRobotics/modules/0_getting_started/3_how_to_contribute.html)