Sync svelte docs (#1957)

sync svelte docs

Co-authored-by: svelte-docs-bot[bot] <196124396+svelte-docs-bot[bot]@users.noreply.github.com>

Author: github-actions[bot]

apps/svelte.dev/content/docs/svelte/02-runes/02-$state.md

@@ -168,6 +168,8 @@ To take a static snapshot of a deeply reactive `$state` proxy, use `$state.snaps
 
 This is handy when you want to pass some state to an external library or API that doesn't expect a proxy, such as `structuredClone`.
 
+If a value has a `toJSON` method, the snapshot will clone the value returned from `toJSON` instead of the original object.
+
 ## `$state.eager`
 
 When state changes, it may not be reflected in the UI immediately if it is used by an `await` expression, because [updates are synchronized](await-expressions#Synchronized-updates).