Update free-programming-books-pt_BR.md (#5091)

fix emberjs link

free-programming-books-pt_BR.md

@@ -22,7 +22,7 @@
   * [Angular](#angular)
   * [Angular.js](#angularjs)
   * [Backbone.js](#backbonejs)
-  * [Ember.js](emberjs)
+  * [Ember.js](#emberjs)
   * [Express.js](#expressjs)
   * [Grunt](#grunt)
   * [Gulp](#gulp)