docs: add custom admin route ranking documentation

[bqst]

Summary

What — What changes are introduced in this PR?

Related PR #13946
Add custom admin route ranking documentation

Why — Why are these changes relevant or necessary?

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How — How have these changes been implemented?

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Testing — How have these changes been tested, or how can the reviewer test the feature?

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Examples

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This helps with documentation and ensures maintainers can quickly understand and verify the change.

// Example usage

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Checklist

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Additional Context

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Note

Adds documentation for rank in admin UI route configs, including sorting rules and nested route ranking, with example tabs; updates corresponding public content.

• Admin UI Routes Docs (app/learn/fundamentals/admin/ui-routes/page.mdx)
  • Add rank to defineRouteConfig properties and explain sidebar ordering.
  • New section: Specify UI Route Sidebar Rank (with version note) and sorting rules.
  • Add examples for ranked routes using CodeTabs/CodeTab (Analytics rank 1, Reports rank 2).
  • Extend nested routes docs with ranking guidance and examples under nested: "/orders".
  • Minor copy tweaks (apostrophe fix in sidebar item text).
• Public content mirror (public/llms-full.txt)
  • Sync the above additions: rank property, ranking section, sorting rules, and nested ranking examples.

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Latest commit: 194f93b

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[vercel]

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[shahednasser]

Thank you for your contribution! Added comments for changes.

Once you're done making changes, can you also run these commands in the www/apps/book directory:

yarn lint:content
yarn prep

And commit the file changes

[shahednasser]

Small fixes remaining

[shahednasser]

LGTM thanks!