docs(demos): add item sliding & option API demo and fix docs for it

references driftyco/ionic-site#397

ionic/components/item/item-sliding.ts

@@ -13,9 +13,9 @@ import {List} from '../list/list';
  * ```html
  * <ion-list>
  *   <ion-item-sliding *ngFor="#item of items">
- *     <ion-item (click)="itemTapped(item)">
+ *     <button ion-item (click)="itemTapped(item)">
  *       {{item.title}}
- *     </ion-item>
+ *     </button>
  *     <ion-item-options>
  *       <button (click)="favorite(item)">Favorite</button>
  *       <button (click)="share(item)">Share</button>
@@ -23,6 +23,7 @@ import {List} from '../list/list';
  *   </ion-item-sliding>
  * </ion-list>
  * ```
+ * @demo /docs/v2/demos/item-sliding/  
  * @see {@link /docs/v2/components#lists List Component Docs}
  * @see {@link ../../list/List List API Docs}
  */

ionic/components/option/option.ts

@@ -10,6 +10,7 @@ import {isDefined, isTrueProperty} from '../../util/util';
  * @property [value] - the value of the option
  * @property [checked] - whether or not the option is already checked and selected
  *
+ * @demo /docs/v2/demos/item-sliding/
  */
 @Directive({
   selector: 'ion-option'