How to work with the code for the book "Design Patterns in PHP and Laravel" by Celt Dawkins?

Question

Laravel

I did not understand how to use the code for the book. The author gives a link to the Github repository. At the beginning of each chapter, you need to do the appropriate git checkout xxx. The repository has app, bootstrap, public, vendor folders, artisan files, composer.json, etc. i.e. looks like an incomplete installation of Laravel. The author recommends installing Laravel after cloning the repository from github. In the folder with the repository, I tried to execute composer update and composer install. I found out that he needed PHP 7.1 (required the MCrypt library), but Laravel never fully got up. Or do I need to install Laravel separately? Then why are there so many additional files in the repository for the book, and not just the source code? Essence of the question: if anyone figured out the author's idea, please share how to deploy related materials. Thanks in advance.