Grammatical fix in scout.md (#10356)

Co-authored-by: Simon Paterson <simon.paterson@bookhouse.com.au>

Author: BhSimon

scout.md

@@ -168,7 +168,7 @@ Additional settings and schema definitions for your Typesense collections can be
 <a name="preparing-data-for-storage-in-typesense"></a>
 #### Preparing Data for Storage in Typesense
 
-When utilizing Typesense, your searchable model's must define a `toSearchableArray` method that casts your model's primary key to a string and creation date to a UNIX timestamp:
+When utilizing Typesense, your searchable models must define a `toSearchableArray` method that casts your model's primary key to a string and creation date to a UNIX timestamp:
 
 ```php
 /**