docs: add label to snapshot example (#9031)

Author: geoffrich

documentation/docs/30-advanced/65-snapshots.md

@@ -21,7 +21,8 @@ To do this, export a `snapshot` object with `capture` and `restore` methods from
 </script>
 
 <form method="POST">
-	<textarea bind:value={comment} />
+	<label for="comment">Comment</label>
+	<textarea id="comment" bind:value={comment} />
 	<button>Post comment</button>
 </form>
 ```
@@ -30,4 +31,4 @@ When you navigate away from this page, the `capture` function is called immediat
 
 The data must be serializable as JSON so that it can be persisted to `sessionStorage`. This allows the state to be restored when the page is reloaded, or when the user navigates back from a different site.
 
-> Avoid returning very large objects from `capture` — once captured, objects will be retained in memory for the duration of the session, and in extreme cases may be too large to persist to `sessionStorage`.
+> Avoid returning very large objects from `capture` — once captured, objects will be retained in memory for the duration of the session, and in extreme cases may be too large to persist to `sessionStorage`.