cleanup(docs): Edited API docs

modules/angular2/annotations.js

@@ -2,6 +2,10 @@
  * @module
  * @public
  * @description
- * Define public API for Angular here.
+ *
+ * Annotations provide the additional information that Angular requires in order to run your application. This module
+ * contains [Component], [Decorator], and [View] annotations, as well as [Parent] and [Ancestor] annotations that are
+ * used by Angular to resolve dependencies.
+ *
  */
 export * from './src/core/annotations/annotations';