adds a third button at main menu
adds a third button at main menu

ruslan120101/TankAttack-JavaFX,ruslan120101/JavaFX-TankAttack,ruslan120101/JavaFX-TankAttack,ruslan120101/JavaFX-TankAttack,ruslan120101/TankAttack-JavaFX,ruslan120101/TankAttack-JavaFX