Description

Migrate docs site building to leverage Storybook. This PR:

• Updates build tooling and yarn commands
• Updates GitHub Actions to target the storybook build as the documentation site
• Removes the *.yml assets from components
• Removes the site package from the project
• Removes the @spectrum-css/site package as legacy styles
• Migrates all assets to .storybook/assets

How and where has this been tested?

Please tag yourself on the tests you've marked complete to confirm the tests have been run by someone other than the author.

Validation steps

• (@rise-erpelding) Pull down the branch and run yarn build:docs locally. Open the /dist/index.html file in the local dev server provided by VSCode. Expect to see a production build of the Storybook site with only docs pages.
• Expect the landing page for the docs site to show the developer build of Storybook (with demo pages)

Regression testing

Validate:

1. The documentation pages for at least two other components are still loading, including:

• The pages render correctly, are accessible, and are responsive.

To-do list

• I have read the contribution guidelines.
• I have updated relevant storybook stories and templates.
• I have tested these changes in Windows High Contrast mode.
• If my change impacts other components, I have tested to make sure they don't break.
• If my change impacts documentation, I have updated the documentation accordingly.
• ✨ This pull request is ready to merge. ✨