scroll docs wip

ionic/components/scroll/scroll.ts

@@ -23,14 +23,25 @@ import {IonicComponent} from '../../config/annotations';
   template: '<scroll-content><ng-content></ng-content></scroll-content>'
 })
 export class Scroll extends Ion {
-  constructor(elementRef: ElementRef, ionicConfig: IonicConfig) {
-    super(elementRef, ionicConfig);
+  /**
+   * TODO
+   * @param {ElementRef} elementRef  TODO
+   * @param {IonicConfig} config  TODO
+   */
+  constructor(elementRef: ElementRef, config: IonicConfig) {
+    super(elementRef, config);
 
     setTimeout(() => {
       this.scrollElement = this.getNativeElement().children[0];
     });
   }
 
+  /**
+   * Add a scroll event handler to the scroll element if it exists.
+   * @param {Function} handler  The scroll handler to add to the scroll element.
+   * @returns {?Function} a function to remove the specified handler, otherwise
+   * undefined if the scroll element doesn't exist.
+   */
   addScrollEventListener(handler) {
     if(!this.scrollElement) { return; }