Update free-programming-books.md (#2360)

free-programming-books.md

@@ -74,6 +74,7 @@
 * [JavaScript](#javascript)
   * [Javascript frameworks](#javascript-frameworks)
   * [Node.js](#nodejs)
+  * [React.js](#reactjs)
 * [Jenkins](#jenkins)
 * [Julia](#julia)
 * [Language Agnostic](#language-agnostic)
@@ -1402,6 +1403,11 @@ For resources on Angular, Backbone, D3, Dojo, Ember, Express, jQuery, Knockout,
 * [The Node Beginner Book](http://nodebeginner.org)
 
 
+#### React.js
+
+* [The Road to learn React - Build a Hacker News App along the Way](https://leanpub.com/the-road-to-learn-react), [Open Source](https://github.com/rwieruch/the-road-to-learn-react)
+
+
 ### Jenkins
 
 * [Jenkins: The Definitive Guide](http://www.bogotobogo.com/DevOps/Jenkins/images/Intro_install/jenkins-the-definitive-guide.pdf) (PDF)