Adding Module Patterns book (#5789)

* Adding Module Patterns

* Update books/free-programming-books-langs.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

books/free-programming-books-langs.md

@@ -1206,6 +1206,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 * [Full Stack JavaScript: Learn Backbone.js, Node.js and MongoDB](https://github.com/azat-co/fullstack-javascript) - Azat Mardan
 * [Introduction to Node.js](https://nodejs.dev/learn) (HTML)
 * [Mixu's Node Book](http://book.mixu.net/node/)
+* [Module Patterns](https://leanpub.com/modulepatterns) - Pedro Teixeira (HTML, PDF, EPUB, Kindle) *(Leanpub account or valid email requested)*
 * [Node Documentation](https://nodejs.org/en/docs/)
 * [Node: Up and Running](https://www.oreilly.com/library/view/node-up-and/9781449332235/) - Tom Hughes-Croucher
 * [Node.js Notes for Professionals](http://goalkicker.com/NodeJSBook) - Compiled from StackOverflow Documentation (PDF)