doc(angular.io): update twitter account (#3197)

Author: Wassim Chegham

public/news.jade

@@ -102,11 +102,11 @@
       .article-card
         .title
           a(
-          href="http://twitter.com/angularjs"
+          href="http://twitter.com/angular"
           class="twitter-follow-button"
           data-show-count="false"
-          ) Follow @angularjs
+          ) Follow @angular
         p.
           <a class="twitter-timeline" data-chrome="nofooter noborders noheader"
-          href="http://twitter.com/angularjs" data-widget-id="700150278465523713"></a>
+          href="http://twitter.com/angular" data-widget-id="700150278465523713"></a>