Merge pull request #2868 from yohanmoon/ym-branch

add instruction for `ModuleNotFoundError: No Module named setuptools`

Author: MyreMylar

docs/README.md

@@ -11,6 +11,7 @@ Steps:
 - Install Sphinx (`pip install Sphinx`)
 - Fork the pygame-ce repository, download and navigate to it in the terminal
 - Run `python setup.py docs`
+     - (Run `python -m pip install -U pip setuptools` first if `ModuleNotFoundError: No module named setuptools` occurs)
 
 This will create a new folder under the `docs` folder. 
 In `docs/generated`, you will find a local copy of the pygame documentation.