Previously the docs order was defined by the default behavior of
Storybook: discovery order. But, in our situation we want the
"Getting Started" part to appear above "Components", and "Doc"
above any other stories. So we needed to create a custom sort callback.
In order to make this storySort callback to be taken into account by Storybook
it was needed to rename the file to preview.js. Strange but .. meh.
Based on the work delivered by designers, we simply replicates those
in the storybook documentation in order to centralize everything
related to the Button component.
These files will be used to define the custom design tokens per components.
They are automatically aggregated by the packages/react/cunningham.ts file,
this is why handling typescript config file was important.
