支持 npm 引入：
https://cdnjs.cloud/npm/package@version/file https://cdnjs.cloud/npm/jquery@3.2.1/dist/jquery.min.js
支持 github 引入:
https://cdnjs.cloud/gh/user/repo@version/file https://cdnjs.cloud/gh/jquery/jquery@3.2.1/dist/jquery.min.js
通用的引入风格：
https://cdnjs.cloud/ajax/libs/repo/version/file https://cdnjs.cloud/ajax/libs/jquery/3.3.1/jquery.min.js
快速的版本选择：
https://cdnjs.cloud/jquery/ https://cdnjs.cloud/npm/jquery/
Google fonts：
<link href="https://cdnjs.cloud/css?family=Open+Sans" rel="stylesheet">