Don't waste space for glyphs that are not full height.

For "Single" through" Squat-T" only two rows of dots are needed to
display the full glyph, so it's wasteful to have a full-size glyph. We
fix this by dynamically computing a correct viewBox for the glyph's
SVG given the dots that are present, and then letting the "glyph"
class styling automatically determine a height based on its children,
rather than explicitly setting it to the full height, assuming a
square.