feat: Add cloudflare pages support

[sushichan044]

As mentioned in this document, some of wrangler.toml keys are different between Worker and Pages.

https://developers.cloudflare.com/pages/functions/wrangler-configuration/#differences-using-wranglertoml-for-pages-functions-and-workers

Do you have any ideas on how to deal with these differences?
The most obvious one would be to have different defineConfig() functions.

[sushichan044]

Hi @sor4chi !
Can I add support for Cloudflare Pages? I would probably add a function like definePagesConfig.

[sor4chi]

@sushi-chaaaan
Oh, I completely forgot about the existence of this issue, sorry.
Of course, contributions are welcome, please!