Choose a more suiting Monospaced font

[aarontabor]

In #76, I changed the font of the "calibration display" debugging bar to a monospaced font to avoid having the message jitter as the numbers were continuously updated. Since we didn't already have a monospaced font in the project, I quickly picked on that looked okay.

Spend some time selecting a monospaced font that matches the current themes of the game.