Modify some front learning materials

Modify some front learning materials

free-programming-books-zh.md

@@ -46,7 +46,7 @@
 * [TeamTreeHouse](http://teamtreehouse.com/)
 * [Udacity](https://www.udacity.com/)
 * [xuetangX](https://www.xuetangx.com/)
-
+* [慕课网](http://www.imooc.com/course/list)(丰富的移动端开发、php开发、web前端、html5教程以及css3视频教程等课程资源)
 
 #### 软件开发方法
 * [傻瓜函数编程](https://github.com/justinyhuang/Functional-Programming-For-The-Rest-of-Us-Cn) (《Functional Programming For The Rest of Us》中文版)
@@ -92,6 +92,7 @@
 * [Linux C 编程一站式学习](http://docs.linuxtone.org/ebooks/C&CPP/c/)
 
 
+
 ### C++
 * [C++ Template 进阶指南](https://github.com/wuye9036/CppTemplateTutorial)
 * [C++ 基础教程](http://www.prglab.com/cms/)
@@ -130,11 +131,14 @@
 ### HTML / CSS
 * [HTML5 教程](http://www.w3school.com.cn/html5/)
 * [学习 CSS 布局](http://zh.learnlayout.com/)
+* [CSS参考手册](http://css.doyoe.com/)
 
 
 ### Javascript
 * [Javascript Garden](http://bonsaiden.github.io/JavaScript-Garden/zh/)
 * [Javascript 原理](http://typeof.net/s/jsmech/)
+* [JavaScript 标准参考教程](http://javascript.ruanyifeng.com/)
+* [ECMAScript 6入门](http://es6.ruanyifeng.com/)
 
 
 ### LaTeX