Update description of changeWidth.

Author: marnusw

README.md

@@ -48,9 +48,9 @@ and the new component animated in. During this process:
 
 This provides many possibilities for animating the replacement as illustrated in the examples below.
 
-Additionally, `changeWidth` can be used to animate changing the width of the component. This change
-will happen at the same time as changing the height. Animating this change should be done using
-the same class name as is used for animating the change of height.
+Additionally, the boolean property `changeWidth` can be used to animate changing the width of the component. 
+This change will happen at the same time as changing the height. Animating this change should be done using
+the same class name as is used for animating the change in height.
 
 It is also possible to remove the child component (i.e. leave `ReactCSSTransitionReplace` with no children)
 which will animate the `height` going to zero along with the `leave` transition. Similarly, a single child