Math font size does not follow the current normal text size

[Omikhleia]

Up to SILE 0.15.5, the math font size is defaulting to 10 (pt) via the math.font.size setting.

While I can understand the need sometimes to adjust the math font size (e.g. based on the look of the target math font), this is a bad default and solution.

• My booklet is typeset in Libertinus 12pt (... getting older, I use bigger font sizes), and uses Libertinus Math for math = Inline formulas are too small...
• One may also expect formulas:
  • in block-quotes (e.g. a quotation from a book, generally typeset in a small font)...
  • or in footnotes... (idem)
  • or even in headers (and hence in the ToC etc.)

So the font size ought to be the same as the normal text size by default, and possibly be adjusted by some ratio, but certainly not in a different and independent size setting (or all commands that tweak the font size would need to also tweak the math font size).

[alerque]

Huh. I could have sworn I fixed this already, but it appears I must have stashed my code somewhere other than an open PR. Oops. I totally agree by default we should start out matching the text default and only allow the setting to be overridden (optionally relative to it).