Update git pr instruction (GH-219)
Update git pr instruction (GH-219)

On Windows, the single and double quotes should be reversed
Closes https://github.com/python/devguide/issues/217

* Clarify that the that the first git pr alias setup is for Unix /MacOS

jython/devguide,jeff5/jython-devguide,jeff5/jython-devguide,ezio-melotti/devguide,jython/devguide,jython/devguide,jeff5/jython-devguide