Feb 2018 文档更新工作

[zsdonghao]

@lgarithm @luomai

• 与英文文档同步，换成 numpydoc 格式
• 去除ops
• 欢迎补充

[lgarithm]

Perhaps there exists some tools which can do the translation, need to find out.

[zsdonghao]

在new-docs branch上更新中