Update README.md

Added Note for building on windows

README.md

@@ -6,4 +6,6 @@ Some code is ported from [pymunk](https://github.com/viblo/pymunk) and much of t
 
 Cymunk should be significantly faster than pymunk and run on android with [p4a](https://github.com/kivy/python-for-android) - but it is currently less feature complete. 
 
-Check out the examples folder, [cymunk docs](http://cymunk.readthedocs.org/en/latest/) and [pymunk docs](https://pymunk.readthedocs.org/en/latest/)
+Check out the examples folder, [cymunk docs](http://cymunk.readthedocs.org/en/latest/) and [pymunk docs](https://pymunk.readthedocs.org/en/latest/)  
+
+To build for windows you should use MinGW - [setup](http://stackoverflow.com/a/5051281/445831) or ```python setup.py build --compiler=mingw32```