Trick question. It's not a thing. It's this guy:
Basically, he wears a top hat, lives in your computer, and waits for you to tell him what kind of application you wish to create.
Not every new computer comes with a Yeoman pre-installed. He lives in the npm package repository. You only have to ask for him once, then he packs up and moves into your hard drive. Make sure you clean up, he likes new and shiny things.
npm i -g yo gulp
npm i -g generator-phaser-coffeescript-gulp
mkdir my-game cd $_ yo phaser-coffeescript-gulp
Once the generator is initiated you are ready to run
Gulp will start a web server with live-reload support using Browser-Sync, compile and merge coffee files.
And you are ready to start developing awesome games right away!
To generate a prefab run
yo phaser-coffeescript-gulp:prefab prefabname. You will see the prefab choices:
Then you can require your newly generated prefab in a state file.
To generate a state run
yo phaser-coffeescript-gulp:state statename.