FEATURE REQUEST: Add "grade" axis to variable font

[seezee]

Requesting "grade" axis (grad) for this font, as well as Merriweather Sans. This would allow a more consistent appearance on sites with light/dark mode toggle.

[EbenSorkin]

I'd love to do this. But It's a non-trivial amount of work. Like 6 months, I think. But if there is money to get it done I would.