Github 更新一个新功能，能让使用 GitHub Pages 发布网站更加简单。现在你可以在你的代码储存仓中选择源代码，然后GitHub Pages 会在这里寻找上下文。
操作示意图：
使用介绍：
Selecting master branch will publish your site from the master branch. This is useful for repositories dedicated to website content. Selecting master branch /docs folder will publish from the /docs folder of your master branch. This lets you maintain documentation and code together on one branch, and open source maintainers can accept contributions for both in a single pull request.
点击这里查看官方使用文档。 详细更新说明：https://github.com/blog/2228-simpler-github-pages-publishing | 
