docs: Add comparison page

[Zamiell]

I think it would be useful to have a comprehensive page comparing Zod, TypeBox, and ArkType, since they all are similar projects, i.e. creating run-time types. It would be nice to have the pros and cons of each solution, and where they differ, and the best use cases for each of them, or something along those lines.

Zod in particular seems to be the most popular solution right now, so I think a page like this helps adoption.

(Also, maybe we should also cover Valibot, which is similar to Zod. But not sure how much traction Valibot is getting lately.)

[floratmin]

I like the expressiveness and conciseness of ArkType very much. I think it can be a very good tool to support domain modeling in a functional way. It feels almost like writing documentation in code.

[ssalbdivad]

Thank you @floratmin! Concision and expressiveness are definitely areas where an embedded syntax has some big advantages over other methods.

There are several other major areas as well, some of which I've enumerated here https://gist.github.com/ssalbdivad/d60d876ab6486adc97e38e3f6916e93f but it's quite out of date at this point.

I will try and write something simple up that summarizes the biggest differences and get that added to the docs soon.