anchor.diff:  .l-main-section
   h1#root-component Step 2: Create the application's root component
   :marked
  +  Every Angular application has at least one component: the _root component_, named `AppComponent`
  +  by convention. The root component hosts the client user experience.
  +
  +  Components are the basic building blocks of Angular applications. A component controls a portion
  +  of the screen&mdash;a *view*&mdash;through its associated template
  +
     **Create #{_an} #{_appDir} subfolder** off the project root directory:
   
   code-example.
  
positive.code: 
  block create-main
    :marked
      Now we need something to tell Angular to load the app module.
      Create the file `app/main.ts` with the following content:
  
  +makeExample('app/main.ts')
  
negative.code:     makes it possible for you to keep payload size small by only importing the parts of Angular
      that your application needs.
  
      Every Angular application has at least one module: the _root module_, named `AppModule` by
      convention.
  
      Create the file `app/app.module.ts` with the following content:
  
  