feat: ✨ provide base set of CSS variables

[karlbaumhauer]

Description

In order to provide a quick fix for #1203, we should just provide the basic color values on our CDN. This would prevent users to copy paste them from our repo and add them to their repo:

• ✅ e. g. --sd-primary-500
• ❌ e. g.--sd-bg-primary-500

This should be provided as a package and on the CDN as well.

DoR

• Item has business value
• Item all subtasks have been estimated by the team
• Item is clear and well-defined
• Item dependencies have been identified

DoD

• All subtasks have been closed