Folder structure

src - source code for your kaboom project
www - distribution folder, contains your index.html, built js bundle and static assets

Development

$ npm run dev

will start a dev server at http://localhost:8000

$ npm run build

will build your js files into www/main.js

$ npm run bundle

will build your game and package into a .zip file, you can upload to your server or itch.io / newground etc.