Update free-programming-books.md
@ -23,7 +23,7 @@
* [Go](#go)
* [Grails](#grails)
* [Haskell](#haskell)
* [HTML / CSS](#HTML / CSS)
* [HTML / CSS](#html--css)
* [Java](#java)
* [JavaScript](#javascript)
* [JavaScript (Node.js specific)](#javascript-nodejs-specific)