Paragraph "Development" (page 14 in the current version) answers your question:

"The entire Crypto 101 project is publicly developed on GitHub under the crypto101 organization, including this book: https://github.com/crypto101/book "

[...]

"The copy of this book that you are reading right now is based on the git commit with hash 3f89ec3 , also known as 0.4.0-22-g3f89ec3"

Then, looking at the commits, yes the book changed a lot since 2014: https://github.com/crypto101/book/commits/master