chore(docs): remove Disqus comments

We don't actively moderate these comments, and they range from
out of date, to inflammatory, to spam. Going forward, improvements
to the docs should be done via a PR, and questions should go on
StackOverflow where they can be curated and kept up to date by
AngularJS developers who help out there.
Merge branch 'master' of https://github.com/angular/angular.js
componentizd!