anchor.diff:  
   .l-main-section
   h2#index Step !{step++}: Define the web page that hosts the application
  -h2#index 步骤!{step++}：定义该应用的宿主页面
  +h2#index 步骤5：定义该应用的宿主页面
   :marked
     In the *#{_indexHtmlDir}* folder,
     create an `index.html` file and paste the following lines into it:
  
positive.code: block includes
    include _util-fns
    - var _Install = '安装'
    - var _Install_cn = '安装'
    - var _prereq = 'Node.js and npm'
    - var _prereq_cn = 'Node.js和npm'
  
negative.code: 
  .l-main-section
  h2#main Step !{step++}: Start up your application
  h2#main 步骤4：启动应用
  
  block create-main
    :marked
  