Create Pause Menu

[BSharp94]

In the game, the player should be able to pause the game and go to a pause menu. There should probably be two ways to pause the game, a pause button in the top right and a key binding (Esc or P).

It might be easiest to copy the background_panning reference and add a pausing option to that.

Additional Questions

1. Should the pause menu be a different scene so we can use the scene.pause() method call?
2. Should we draw the menu in a function using phaser 3 or should we create an asset to draw the menu and options with tile?