Make it clear that Next.js's idea of a "static" page and CloudFlare's idea of a "static" page are very different things

### Proposed changes

- https://developers.cloudflare.com/workers/framework-guides/web-apps/nextjs/

### Subject Matter

What Next.js means by static and how that's not the same as Worker Assets

### Content Location

Not sure where in the document, but somewhere in the Next.js framework guide linked above

### Additional information

Unless using `export`, Next.js static pages are still served by the Next.js server, therefore even "static" page hits result in Worker invocations on CloudFlare and static page content will count towards the size of the Worker JS bundle, even though Next.js calls it "static." I think this either needs to be more clearly explained in the documentation and/or (ideally!) improved by the CloudFlare team (surely there must be some way to get static pages out of the Worker js and serve them, you know, statically?). Thanks for your consideration, Mr(s). Flare