Fix sample gif link

README.md

@@ -10,8 +10,7 @@
 
 A toolkit for building rich console apps for .NET, .NET Core, and Mono that works on Windows, the Mac, and Linux/Unix.
 
-![Sample app](https://raw.githubusercontent.com/gui-cs/Terminal.Gui/docfx/images/sample.gif)
-
+![Sample app](https://gui-cs.github.io/Terminal.Gui/images/sample.gif)
 
 ## Documentation