5-15-25: Fixes and Tutorial

Bugs Fixed: 

• Dog getting caught in sheep's motion
• Quit Button doing nothing - Quit button now takes you to the main menu, and try again reloads the previous scene

Polish:

• Background color changed 
• Barn sprite updated to make the goals of the game more clear
• Particle effect added to barn when sheep enter it -- this is to make it more clear when the player is successful
• Tutorial added to the beginning of the game