Update README.md

README.md

@@ -22,7 +22,7 @@ As you are going to run StarWorth in the PHP process context, using a limited we
 
 ## Screenshot:
 
-![StarWorth in action #1](/SW_res/screenshot1.png)<br><br><br>
+![StarWorth in action #1](/SW_res/screenshot1.jpg)<br><br><br>
 
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