Missing `@sveltejs/kit/*` docs

[Rich-Harris]

Describe the bug

The docs include a section for the generated modules ($app/*, $lib and $service-worker) but not the @sveltejs/kit/* ones: https://kit.svelte.dev/docs#modules

We should add some. Not sure where the best place for it is. We can probably omit adapter-utils since that will presumably become obsolete with #2215.

Reproduction

visit https://kit.svelte.dev/docs, look for the docs, find no docs

Logs

No response

System Info

N/A

Severity

annoyance

Additional Information

No response

[benmccann]

I think this is mainly just import { sequence } from '@sveltejs/kit/hooks';, so we should probably put that with the handle docs