introductionf翻译初稿

Test Plan: 翻译审阅

Reviewers: #phabricator文档翻译团

Differential Revision: http://review.d.xiaonei.com/D3
翻译初稿
中文翻译前言

Summary: 推荐所有翻译人员查阅并且持续更新

Test Plan: 语法检查

Reviewers: #phabricator文档翻译团, shaokun.shi, sijia.li, guanhui.fu

Reviewed By: #phabricator文档翻译团, shaokun.shi, sijia.li, guanhui.fu

Differential Revision: http://review.d.xiaonei.com/D4