Add hostname routing documentation for Workers for Platforms

[dinasaur404]

Summary

• Add a page to document how to route custom hostnames/subdomain traffic to the dispatch worker
• Document o2o traffic behavior with routes

Screenshots (optional)

Documentation checklist

• [X ] The documentation style guide has been adhered to.

[hyperlint-ai]

Howdy and thanks for contributing to our repo. The Cloudflare team reviews new, external PRs within two (2) weeks. If it's been two weeks or longer without any movement, please tag the PR Assignees in a comment.

We review internal PRs within 1 week. If it's something urgent or has been sitting without a comment, start a thread in the Developer Docs space internally.

---

PR Change Summary

Added documentation for routing custom hostnames and subdomains to dispatch workers, including setup instructions and behavior for Orange-to-Orange traffic.

• Introduced a new page on hostname routing for Workers for Platforms.
• Documented the setup process for routing custom hostnames and subdomains.
• Explained Orange-to-Orange (o2o) traffic behavior and its implications for routing.

Added Files

• src/content/docs/cloudflare-for-platforms/workers-for-platforms/get-started/hostname-routing.mdx

---

How can I customize these reviews?

Check out the Hyperlint AI Reviewer docs for more information on how to customize the review.

If you just want to ignore it on this PR, you can add the hyperlint-ignore label to the PR. Future changes won't trigger a Hyperlint review.

Note specifically for link checks, we only check the first 30 links in a file and we cache the results for several hours (for instance, if you just added a page, you might experience this). Our recommendation is to add hyperlint-ignore to the PR to ignore the link check for this PR.

[dinasaur404]

Closing in lieu of #23361