Add guide on how to deploy Vike on Cloudflare

[brillout]

Summary

This PR adds a guide on how to deploy Vike apps on Cloudflare.

Screenshots (optional)

https://imgur.com/a/IruXQRe

Documentation checklist

• The documentation style guide has been adhered to.
• If a larger change - such as adding a new page- an issue has been opened in relation to any incorrect or out of date information that this PR fixes.
• Files which have changed name or location have been allocated redirects.

[brillout]

I'm closing this PR for now — Cloudflare's official recommendation is to use Cloudflare Workers but this PR creates an app that uses Cloudflare Pages. I'll re-open the PR once Vike's official integration uses Cloudflare Workers and @cloudflare/vite-plugin (which we're actively working on).

[brillout]

I'll re-open the PR once Vike's official integration uses Cloudflare Workers and @cloudflare/vite-plugin

Done: #26345.