To learn what yeoman is go here: Yeoman generator
The Kiwi.js Yeoman Generator lets you easily create a blank game from a template. It sets up the folder structure and all the files you need to get going.
You'll need to install node.js. Make sure you have git installed and referenced in your path.
To install the kiwi.js generator
$ npm install -g generator-kiwijs
You're now ready to start generating game templates.
1 Create a folder for your game and navigate into that folder
2 Initiate the generator
$ yo kiwijs:app
3 Answer the questions that Yeoman asks you.
4 Wait for Yeoman to install your game.
5 Run grunt to build your game
$ grunt
6 Optionally you can the following to start a server on localhost:9000 which serves your game
$ grunt serve