fix(packages/ui): Use shared CSS for docs and improve UI library structure

[0xTxbi]

Description

This PR updates our docs to use shared CSS from our UI package for consistent styling. It also improves the UI library structure to support this change.

ScreenGrab

Issues

Fixes #15083
Refs #15083

Checklist:

• 1 PR, 1 purpose: my Pull Request applies to a single purpose
• I have commented my code, particularly in hard-to-understand areas
• I have updated the docs to reflect my changes if applicable
• I have added tests (and stories for frontend components) that prove my fix is effective or that my feature works
• I have performed a self-review of my own code
• If my code involves visual changes, I am adding applicable screenshots to this thread

[julien51]

Very cool! Are you sure this looks great "in general? I see it on the page to burn tokens, but what about the other pages?

[0xTxbi]

Very cool! Are you sure this looks great "in general? I see it on the page to burn tokens, but what about the other pages?

absolutely!