book, site and code have hard dependencies

[durrantm]

Thank You for all your hard work on this vital book!

I'm two third of the way through the book and encountering a few problems at once:

• There is no 'before' and after' code for each chapter. This means you have to get every chapter 'right' or you may easily have something broken that stops you dead in your tracks for the rest of the book. Please consider 'before' state for each chapter.
• Similarly, copying package.json, index.html and other files 'from the previous chapter' is impossible if I didn't get the previous chapter working correctly. The github site has the end code but that is from the end of the book. I does work however once I did the npm install for cross-env
• No chapter numbers in my kindle book makes references really hard.
• These problems were significant in trying to do the redux chapter which depended on a lot of things to be right from previous work.