Update Readme.md

Readme.md

@@ -9,6 +9,8 @@ This library implements a numeric up down WPF control that can be used to edit i
 
 There is a demo application that shows the usage of the control (LIght/Black themes enabled) and documents the features, such as, the ability to configure a minimum and maximum value that can be used to keep the resulting value within a given bound.
 
+<img src="https://github.com/Dirkster99/Docu/blob/master/numericupdown/numericupdown_demo.png"/>
+
 ## Theming
 
 Load *Light* or *Dark* brush resources in you resource dictionary to take advantage of existing definitions.