Guide/tutorial: Cloudflare integration for DDOS protection etc.

### What problem are you trying to solve?

Somewhat related to [this](https://github.com/denoland/deploy_feedback/issues/536) issue.

I'm looking at ways to secure my endpoints in Deno Deploy, especially when it comes to DDOS attacks and other exploits. Looking at some of Cloudflare's products, there's a few there that seem relevant, e.g.:

- https://www.cloudflare.com/ddos/
- https://www.cloudflare.com/application-services/products/waf/
- https://www.cloudflare.com/application-services/products/api-gateway/
- https://www.cloudflare.com/application-services/products/rate-limiting/

I'm sure some of you people are working on such features in-house already, but in the mean time I think a decent guide/tutorial on e.g. [Tutorials](https://docs.deno.com/deploy/tutorials/) would be really helpful, and might remove some fear-of-deployment mental blockers some users might have.

### Describe the solution you'd like

A new Deploy Tutorial guiding users through a basic Cloudflare setup that protects their origins and mitigates DDOS attacks.

### Describe alternatives you've considered

Writing it myself. I'm thinking of doing that, but it'd be more of a research article as I don't have enough experience with this to provide a proper guide with 100% confidence.

### Documentation, Adoption, Migration Strategy

_No response_