message: docs(aio): remove ngATL banner from homepage
  Closes
  PR Close
diff: <div class="home-rows">
  - <!-- Announcement Bar -->
  - <div class="homepage-container">
  - <div class="announcement-bar">
  - <img src="generated/images/marketing/home/ng-atl.png">
  - <p>Join us in Atlanta for ngATL<br>Jan 30 - Feb 2, 2018</p>
  - <a class="button" href="http://ng-atl.org/">Learn More</a>
  - </div>
  - </div>
  -
  <!-- Group 1 -->
  <div layout="row" layout-xs="column" class="home-row homepage-container">
  <div class="promo-img-container promo-1">
  