[Docs] API Overview version selector navigates to incorrect link

[ria-ahyoung]

Description

When switching to legacy version (ex. v6) in the API documentation page, the link navigated is incorrect and leads to a 404 not found.

Specifically, the link uses …/6/api instead of …/v6/api.

• Broken link:
  http://react-hook-form-website-git-leagcy-hook-form.vercel.app/6/api
• Correct link should be:
  http://react-hook-form-website-git-leagcy-hook-form.vercel.app/v6/api

Steps to Reproduce

1. Go to https://react-hook-form.com/docs

2. In the version switcher (bottom or top), select v6

   

3. The resulting URL is invalid / 404

   

Expected Behavior

Selecting v6 should navigate to the correct v6 docs path (e.g. /v6/api) rather than /6/api.

Additional Context / Details

• Other version (v5) is similarly affected.
• Fixing the path prefix (adding v before the version number) should resolve the 404.