Well, I'm the opposite of an expert, but I think if you want to help
out from Windows then you are going to have more of a struggle than if
you were working on a Mac or a Linux box.
Have a look at the file readme.md which I think is at the top level of
the code you've checked out. That should tell you what you need to
install in order to get the code running.
You can get Ruby and Gem on Windows -- google for "ruby instant
install". I don't know about the rest, though. Someone more
knowledgable want to come in and rescue me on this one?