Allow defining variants values with attributes or functions

[thiagomajesk]

Right now, you can only do something like: variant :color, [blue: "text-blue-500"] and not variant :color, @text_colors because the macro is not expanding the module attribute. Would you be willing to support a similar syntax? This seems very helpful for cases where you want to share the variant definitions between similar components.

[benvp]

Sorry for answering extremely late. This sounds like a reasonable thing to do. Would you be willing to create a PR for this?