Update errors.md

Co-authored-by: Simon H <[email protected]>

Author: elliott-with-the-longest-name-on-github

packages/svelte/messages/shared-errors/errors.md

@@ -71,9 +71,9 @@ A component throwing this error will look something like this (`children` is not
 ```svelte
 <!--- file: Parent.svelte --->
 <ChildComponent>
-  {#slot label()}
+  {#snippet label()}
     <span>Hi!</span>
-  {/slot}
+  {/snippet}
 </ChildComponent>
 ```