I wasn't sure what IntroJS was, I think this is what the book is about http://usablica.github.io/intro.js/ http://usablica.github.io/intro.js/, but do we really

I wasn't sure what IntroJS was, I think this is what the book is about http://usablica.github.io/intro.js/ http://usablica.github.io/intro.js/, but do we really need a book to explain it?