Add option to add type of style to the variable name

[FractalThought]

At the moment, the variable name is exported as-is, which can cause issues if you have for example a text style named primary, and a color style named primary.

Even without the same naming, it can be useful to get variables with the type of style.

Suggestion:
Add option to add type of style to the variable name;
--text-primary
--color-primary
--effect-primary