docs: step 6 of tutorial use a href rather than an ng-href

[EthanLozano]

step_06.ngdoc uses a dynamically generated link with the href attribute rather than the ng-href attribute.

[EthanLozano]

The Phonecat tutorial source code and tag needs to be changed first. So, I went ahead and created an issue for that repo.

[dguzzo]

@Narretz hmm, not sure how #10850 being merged will fix the issue with the docs here; regardless of parsing, shouldn't the example in the tutorial still use ng-href for the dynamic link? I'm probably missing something.

[Narretz]

It looks like I referenced the wrong issue to close.

[petebacondarwin]

This is not really necessary as it is unlikely that the user will click on a link before Angular has had time to fill it correctly.