[Spike] Restructure Styling Docs IA

[alanbsmith]

🔍 Spike

Canvas Kit Styling is bigger than we originally anticipated. It feels like it doesn't fit well in our current Storybook IA. This spike should help us answer:

• Where should styling documentation live?
• How should it be structured?
• What content should be covered?
  • What are we currently missing?

Deliverable

Make a recommendation to the team on where Canvas Styling documentation should live, what content it should include, and how it should be structured.