Implement Style dictionary for design tokens

[bramsmulders]

Many teams are using design tokens in their design tools, websites, apps. Currently supple-css is Sass based and has a non standard configuration model.

We want to move away from Sass and go native CSS, but we want to maintain the possibility for custom configuration. Style dictionary is ideal for those purposes: https://styledictionary.com

We want to ensure styledictionary creates a correct output which can be consumed by supple-css modules & by every web project which implements it. Ideally every token is available as a custom property in the codebase.