Setting up navigation

The original app component (app/app.component.ts) should only handle navigation now. So edit the app/app.component.ts file so that it contains the following TypeScript code:

import { Component } from '@angular/core'; 
import { ROUTER_DIRECTIVES }  from '@angular/router'; 
@Component({ 
    selector: 'my-app', 
    template: `<ul> 
    <li><a [routerLink]="['/home']" routerLinkActive="active">Home</a></li> 
    <li><a [routerLink]="['/features']" routerLinkActive="active">Features</a></li> 
    <li><a [routerLink]="['/pricing']" routerLinkActive="active">Pricing</a></li> 
    <li><a [routerLink]="['/about']" routerLinkActive="active">About</a></li> 
    </ul> 
    <router-outlet></router-outlet>`, 
  ...