title: Trying to understand redirect route example
body: <p>From the docs
  <a href="https://angular.io/guide/router" rel="nofollow noreferrer">https://angular.io/guide/router</a></p>
  
  <p>What does the route with '**' do? What do the two asterisks correspond to?</p>
  
  <pre><code>const appRoutes: Routes = [
    { path: 'crisis-center', component: CrisisListComponent },
    { path: 'heroes',        component: HeroListComponent },
    { path: '',   redirectTo: '/heroes', pathMatch: 'full' },
    { path: '**', component: PageNotFoundComponent }
  ];
  </code></pre>