do not show animated GIF in readme immediately

embedding videos is not supported for markdown, this is a workaround and an option for further video requirements, as mentioned in #13

Author: PhilippSalvisberg

README.md

@@ -4,7 +4,7 @@
 
 utPLSQL for SQL Developer extends Oracle's SQL Developer by context menu entries and keyboard shortcuts for running utPLSQL unit tests from the Connections window or the PL/SQL editor.
 
-![utPLSQL for Developer Demo](utPLSQL.gif)
+[![utPLSQL for SQL Developer Demo](utPLSQL.png)](utPLSQL.gif)
 
 ## Releases