The plugin is used to add .html (extension) in all page URL
该插件用于在所有页面URL中添加.html（扩展名）
Before: http://www.example.com/about-us
之前：http://www.example.com/about-us After: http://www.example.com/about-us.html
之后：http：//www.example.com/about-us.html Our Services as below:
我们的服务如下：
