feat: Redirect management

[swernerx]

Summary

Add built-in redirect configuration for handling URL changes when pages are moved or renamed.

Motivation

As documentation evolves, pages get renamed, reorganized, or removed. Without redirects, existing links (from blog posts, Stack Overflow, bookmarks) break. Mintlify has built-in redirect configuration. This is essential for maintaining SEO and user experience.

Proposed Configuration

// in ardo config or docs.json
ardo({
  redirects: [
    { from: '/old-page', to: '/new-page' },
    { from: '/guide/setup', to: '/getting-started' },
    { from: '/api/v1/*', to: '/api/v2/*' },
  ]
})

Or via frontmatter on the target page:

---
redirectFrom:
  - /old-path
  - /another-old-path
---

Implementation

For static sites (Ardo's primary use case):

• Generate client-side redirect pages (HTML meta refresh + JS redirect)
• Generate _redirects file for Netlify
• Generate vercel.json redirects for Vercel
• Wildcard/pattern support for bulk redirects