Adding fix from EwertonJordao and also analytics code

Added a free download link for Chapter 1 and updated the reviews to include some reviews from 4th Edition

Updating url for code

More tweaks

Adding new inside the book images and style tweaks

Updates to build so no hash on files. Also couple of code chapter changes

Tweaks to config to get TS compiling in build

Thanks Lucy! Lot's of typos fixed

amendments to make ts build

Updating links and tweaking text

Updating README

Updating titles and minor code amends

initial commit