Support for Global Design Tokens

Hey Rive! We would love to see support for defining Global Tokens, similar to Figma, that would allow for reusable value references across multiple animation projects in the same workspace.

For example, with Color Token support, I would be able to select text-primary in any Color pop-up and automatically have it use the #000000 color that I have added as text-primary.

It would be useful to, then, have Light/Dark mode toggling supported for the usage of these tokens. This way, I can define #000000 as my Light mode text-primary token and #FFFFFF as my Dark mode text-primary token. As of now, we have been using a boolean value to manually swap between colors for Light/Dark mode support but I could see this being supported at the editor and runtime level as Light/Dark mode is very common in mobile apps these days!

This would be most immediately helpful for defining color tokens but I could see the system also being expanded to include px sizing tokens as well (S, M, L, XL, etc.) for padding between elements.

Thanks for all that you do!