docs(googlemaps): improve usage

src/plugins/googlemaps.ts

@@ -48,14 +48,44 @@ export const GoogleMapsAnimation = {
  * ```
  * import { GoogleMap, GoogleMapsEvent } from 'ionic-native';
  *
- * ...
+ * // create a new map using element ID
+ * let map = new GoogleMap('elementID');
  *
- * // somewhere in your component
- * let map = new GoogleMap('elementID', {
- *  // Map Options: https://developers.google.com/maps/documentation/javascript/3.exp/reference#MapOptions
- });
+ * // or create a new map by passing HTMLElement
+ * let element: HTMLElement = document.getElementById('elementID');
  *
+ * // In Angular 2 or Ionic 2, if we have this element in html: <div #map></div>
+ * // then we can use @ViewChild to find the element and pass it to GoogleMaps
+ * @ViewChild('map') mapElement;
+ * let map = new GoogleMap(mapElement);
+ *
+ * // listen to MAP_READY event
  * map.on(GoogleMapsEvent.MAP_READY).subscribe(() => console.log('Map is ready!'));
+ *
+ *
+ * // create LatLng object
+ * let ionic: GoogleMapsLatLng = new GoogleMapsLatLng(43.0741904,-89.3809802);
+ *
+ * // create CameraPosition
+ * let position: CameraPosition = {
+ *   target: ionic,
+ *   zoom: 18,
+ *   tilt: 30
+ * };
+ *
+ * // move the map's camera to position
+ * map.moveCamera(position);
+ *
+ * // create new marker
+ * let markerOptions: GoogleMapsMarkerOptions = {
+ *   position: ionic,
+ *   title: 'Ionic'
+ * };
+ *
+ * map.addMarker(markerOptions)
+ *   .then((marker: GoogleMapsMarker) => {
+ *     marker.showInfoWindow();
+ *   });
  * ```
  */
 @Plugin({