rename and clear
clear docs
added ex2.1~ex2.8
try to add disqus
added 2.9~2.14
Update index.md
added 2.15~2.25
added ex2.26~2.32
add ex2.33~2.35
added ex2.36~2.38
Merge remote-tracking branch 'upstream/master'
Finish ch2 :beer:
Update ex2.39_2.42.md
Merge pull request #5 from pezy/master

:beers: Finished Chapter 2.