The source code package contains a number files and folders at the root. The dist folder contains the compiled es5 JavaScript and map files. The js folder contains all of the example code that we'll be working with in the course. It contains a series of files that map to individual lessons, and it should be clear which file matches which lesson by the filename.
There is also a babel configuration file, a grunt configuration file and a HTML page for testing purposes. This page links to the babel-polyfill and in some lessons we link to the compiled es5.js file, while in other lessons we make use of the es6.js file.
To set things up ready, navigate to the directory that the source code is unpacked to with a command line or terminal and run the npm install command to install Babel.