Expose each typographic semantic text crop values as tokens.

[fraincs]

Given the way that font works on the web, https://medium.com/eightshapes-llc/cropping-away-negative-impacts-of-line-height-84d744e016ce, many developers use a "trick" to remove unwanted top and bottom space.

The solution is rather simple but, without the power of mixins, requires very specific values on every font-size/line-height combinations.

I propose to expose each typographic semantic text crop values as tokens --hop-heading-3xl-text-crop-top --hop-heading-3xl-text-crop-bottom, these values would be documented.

When Hopper will have text components, these would be consumed by the components.