Add some blurb about responsive to readme

Author: BTMorton

README.md

@@ -62,7 +62,7 @@ The defaults for the grid item are:
 #### Styling
 ------------
 
-There are three elements that can be styled with angular2-grid, the grid itself `.grid`, the items `.grid-item` and the placeholder `.placeholder`. The demo includes some basic styling in NgGrid.css which you can include in you app `styleUrls` property. In order for correct functionality, the required styles are added by the classes themselves at run-time:
+There are three elements that can be styled with angular2-grid, the grid itself `.grid`, the items `.grid-item` and the placeholder `.placeholder`. The demo includes some basic styling in NgGrid.css which you can include in your app's `styleUrls` property. It also includes some @media queries styles to handle responsiveness on smaller screens. This simple force the boxes to full width and puts them inline in their original order. This is optional functionality and does not need to be included. In order for correct functionality, the required styles are added by the classes themselves at run-time:
 
 ```css
 .grid {