API reference uplift

[jstirnaman]

Improve API reference docs for UX and performance. Replace ReDoc

To do:

• [x] Generate Hugo pages for endpoints and OpenAPI operations in the spec.
• [x] Use Rapidoc to render generated spec pages
• [x] Implement theme switching.
• [x] Set API server to the user's configured docs site URL.
• [ ] Show page title
• [ ] Use tag name as nav link
• [ ] Use tag name as page title
• [ ] Expand/collapse API servers section
• [ ] Use only one tag per path--provides a title-name and description for the path
• [ ] Add Using the <name> API page with traitTag content
• [ ] Remove traitTags from paths
• [ ] Move related links from description body to related frontmatter
  • [ ] Replace or ReDoc endpoint tag references with new URLs
  • [ ] Replace or alias outdated and broken site links.
• [ ] Fix nested scrollbar
• [ ] Fix styles
• [ ] Fix index page descriptions (use Rapidoc mini or docs-native endpoint shortcode)