update folder-content img on 01.project_setup.rst (#7851)

update folder content img

getting_started/first_2d_game/01.project_setup.rst

@@ -36,7 +36,7 @@ When creating the new project, you only need to choose a valid *Project Path*. Y
 
 Your project folder should look like this.
 
-.. image:: img/folder-content.png
+.. image:: img/folder-content.webp
 
 This game is designed for portrait mode, so we need to adjust the size of the
 game window. Click on *Project -> Project Settings* to open the project settings