Fixed demo reference into documentation

Author: malcommac

README.md

@@ -75,7 +75,7 @@ If you have a long list of rows you may experience delays.
 
 So, `ScrollStackController` is generally not appropriate for screens that contain many views of the same type, all showing similar data (in these cases you should use `UITableView` or `UICollectionView`).
 
-![](./Resources/demomovie.mp4)
+<video src="./Resources/demomovie.mp4" width="278" height="568" controls preload></video>
 
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