Check if the border threshold work fine in multiple screens

[iamgabrielma]

Currently:

        /// Screen bottom threeshold to score
        if ball.position.y <= (mainPaddle.position.y - 20 ){
            addScore(playerWhoWon: enemyPaddle)
        }
        /// Screen top threeshold to score
        else if ball.position.y >= (enemyPaddle.position.y - 20 ){
            addScore(playerWhoWon: mainPaddle)
        }

That -20 might need to be adjusted.