[Feature] Config option for default profile to allow mixed-case text

[racingmars]

One suggestion = when using 1403 paid for font in vprinter.NewProfile(...) instead of forcing uppercase like you do in retro treat it like you treat modern (IBMPlex) as the slanted hall 1403 typeface uses small caps for lower so... you'll get lower and upper like you do for Plex rather than forcing upper when there doesn't appear to be a need.

Originally posted by @rwboyer in #6 (comment)