Update content/docs/reference/types/reference.mdx

Co-authored-by: Isaac Lombard [SSW] <152236421+isaaclombardssw@users.noreply.github.com>

content/docs/reference/types/reference.mdx

@@ -143,7 +143,7 @@ You can search your reference with reference selector.
 
 ### Filter reference
 
-If you have a long list of reference item, you can filter them in the schema before build time using `ui.collectionFilter`
+If you have a long list of reference items, you can filter them in the schema before build time using the `ui.collectionFilter` field.
 
 > Senario: You have a list of author in different location, and you only want the reference select in your post collection to show the desired location.