docs: Tour of Heroes: Incomplete code example #18078

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[ ] Bug report  
[ ] Feature request
[x] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question

Current behavior

On page: https://angular.io/tutorial/toh-pt5#select-a-dashboard-hero
The code sample under: src/app/dashboard.component.html (repeated tag)
The code sample is incomplete and only shows:

<a *ngFor="let hero of heroes"  [routerLink]="['/detail', hero.id]"  class="col-1-4">

The anchor tag is missing its closing </a> that even the copy link in the code doesn't have.
If a user copies this as-is into their project file, they'll get a runtime error about a missing </div> tag.

Expected behavior

Should be what's in the downloaded example:

1  <a *ngFor="let hero of heroes" [routerLink]="['/detail', hero.id]"  class="col-1-4">
2    <div class="module hero">
3      <h4>{{hero.name}}</h4>
4    </div>
5  </a>

Minimal reproduction of the problem with instructions

Download the example zip file, remove lines 2-5 from the example above in the dashboard.component.html file and run the app.

What is the motivation / use case for changing the behavior?

Reduce new user confusion in learning Angular.

Environment

Angular version: 4.0.0

Browser:
- [x] Chrome (desktop) version XX
- [ ] Chrome (Android) version XX
- [ ] Chrome (iOS) version XX
- [ ] Firefox version XX
- [ ] Safari (desktop) version XX
- [ ] Safari (iOS) version XX
- [ ] IE version XX
- [ ] Edge version XX