Adding the demo gif to the repository.

README

@@ -50,11 +50,9 @@ entry.  Each line can be indented with tabs to represent nested menus.
 Each line is made out of a label and a command separated by any number
 of tabs.  Lines without labels are menu separators.
 
-See the script ./xmenu.sh for an example of how XMenu can be used to
-draw a simple menu with submenus and separators.   The following gif
-shows how the menu generated by that script looks like.
-
-	https://i.redd.it/lxv7jewcwmz41.gif
+See the script ./xmenu.sh for an example of how to use XMenu to draw a
+simple menu with submenus and separators.  The file ./demo.gif shows how
+the menu generated by that script looks like.
 
 Read the manual for more information on running XMenu.