Support "font-variation-settings" for variable fonts

[lobau]

A lot of fonts these days are variable (some example here) https://v-fonts.com/

It requires the font-variation-settings CSS variable to change things like optical size, width, weight, and much more.

For example, the volumetrics logo uses those parameters for Bricolage Grotesque

font-variation-settings: 'opsz' 100, 'wght' 800;

[lobau]

would still like to see this one at some point, as our brand fonts are all variable 👀