docs: Use correct defaultItems in the React Slash Menu Example (#179)

* use correct defaults

* Small formatting fix

---------

Co-authored-by: Matthew Lipski <[email protected]>

Author: niclas-j

packages/website/docs/docs/slash-menu.md

@@ -44,12 +44,15 @@ BlockNote comes with a variety of built-in Slash Menu items, which are used to c
 If you want to change, remove & reorder the default items , you first import and copy them to a new array. From there, you can edit the array how you like, then pass it to `useBlockNote`:
 
 ```typescript
-import { defaultSlashMenuItems } from "@blocknote/core";
-import { BlockNoteView, useBlockNote } from "@blocknote/react";
+import { 
+  BlockNoteView,
+  defaultReactSlashMenuItems,
+  useBlockNote
+} from "@blocknote/react";
 import "@blocknote/core/style.css";
 
 function App() {
-  const newSlashMenuItems: ReactSlashMenuItem[] = defaultSlashMenuItems;
+  const newSlashMenuItems: ReactSlashMenuItem[] = defaultReactSlashMenuItems;
 
   // Edit newSlashMenuItems
   ...