Added onOverlayPress to README

Author: Ajackster

README.md

@@ -90,6 +90,7 @@ Also this example uses `react-native-vector-icons` for the button Icons.
 | outRangeScale  | number        | 1                   | changes size of button during animation
 | onPress        | function      | null                | fires, when ActionButton is tapped
 | onLongPress    | function      | null                | fires, when ActionButton is long pressed
+| onOverlayPress | function      | null                | fires, when Overlay is pressed
 | icon           | Component     | +                   | Custom component for ActionButton Icon
 | backdrop       | Component     | false               | Custom component for use as Backdrop (i.e. [BlurView](https://github.com/react-native-fellowship/react-native-blur#blur-view), [VibrancyView](https://github.com/react-native-fellowship/react-native-blur#vibrancy-view))
 | degrees        | number        | 135                 | degrees to rotate icon