Update README.md

Change
DB::collection('items')->project(['tags' => array('$slice' => 1]))->get();
To
DB::collection('items')->project(['tags' => array('$slice' => 1)])->get();

README.md

@@ -885,7 +885,7 @@ DB::collection('users')->where('name', 'John')
 You can apply projections to your queries using the `project` method.
 
 ```php
-DB::collection('items')->project(['tags' => array('$slice' => 1]))->get();
+DB::collection('items')->project(['tags' => array('$slice' => 1)])->get();
 ```
 
 **Projections with Pagination**