fix some typos in chapter 3
Merge pull request #6 from jinglong/master

fix some typos in chapter 3 (thanks to huangjianfu)
Merge pull request #7 from fanjizhao/75ed55650703f890b9d3b8b0590744765efcae05

Added the content of nginx config system in chapter 2.
Update source/chapter_02.rst
Update source/chapter_02.rst

错别字
Merge pull request #8 from nkysg/master

fix typos in chapter 2. thanks to nkysg.
Update source/chapter_03.rst
Merge pull request #9 from nkysg/master

路径分隔符不小心写错了。 thanks to nkysg
Update source/chapter_05.rst
Merge remote branch 'taobao/master'