Adding tweens to the pause menu

Now that we have finished the main menu, let’s continue adding tweens to the pause menu:

1. Go ahead and open up our Gameplay scene. Update the PauseScreenBehaviour script to have the following implementation of SetPauseMenu:

   /// <summary>
       /// Will turn our pause menu on or off
       /// </summary>
       /// <param name="isPaused">is the game currently
       /// paused</param>
       public void SetPauseMenu(bool isPaused)
       {
           paused = isPaused;
           /* If the game is paused, timeScale is 0,
              otherwise 1 */
           Time.timeScale = (paused) ? 0 : 1;
           ...