Update README.md

Author: rusenaite

README.md

@@ -2,7 +2,7 @@
 
 A modern, responsive application for generating random groups from a list of students. Perfect for classroom activities, team assignments, or any scenario where you need to create balanced groups quickly.
 
-![Groupify Demo](demo.png)
+![Groupify Demo](demo.gif)
 
 ## Features
 
@@ -26,4 +26,4 @@ A modern, responsive application for generating random groups from a list of stu
 3. **Generate Groups**: Click the "Generate Groups" button to create random groups
 4. **View Results**: See generated groups with unique names in the right panel
 
-Created with ❤️
+Created with ❤️