Add a fixed width font for text

[karlwilcox]

Text placed in different locations on the shield can appear at different sizes due to scaling words of different length. If we had a fixed width font (and made sure the words had the same number of characters, e.g. "Left " and "Right") then text should appear at the same size. Need to find a suitably licenced fixed width font, available as SVG glyphs with hopefully quite a wide character set....