docs: migrate <svelte:document> to use attachment instead of action (#17749)

## Motivation

noticed that the documentation for the `<svelte:document>` still refers
to actions - probably would be better for beginners if it referred to
the newer attachments instead.

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documentation/docs/05-special-elements/03-svelte-document.md

@@ -10,12 +10,12 @@ title: <svelte:document>
 <svelte:document bind:prop={value} />
 ```
 
-Similarly to `<svelte:window>`, this element allows you to add listeners to events on `document`, such as `visibilitychange`, which don't fire on `window`. It also lets you use [actions](use) on `document`.
+Similarly to `<svelte:window>`, this element allows you to add listeners to events on `document`, such as `visibilitychange`, which don't fire on `window`. It also lets you use [attachments](@attach) on `document`.
 
 As with `<svelte:window>`, this element may only appear the top level of your component and must never be inside a block or element.
 
 ```svelte
-<svelte:document onvisibilitychange={handleVisibilityChange} use:someAction />
+<svelte:document onvisibilitychange={handleVisibilityChange} {@attach someAttachment} />
 ```
 
 You can also bind to the following properties: