Updating readme.

Author: mehradsadeghi

README.md

@@ -10,7 +10,7 @@ It works based on your `$fillable` property of the target model.
 If you would like to use `$guarded` instead of `$fillable`, It is supported too. 
 In that case you'll need to have an existing `Schema` (table), Then the crud generator will autimatically figures out your fillables.
 
-As an example when `$fillables` is available:
+As an example when `$fillable` is available:
 
 `$ php artisan make:crud UserController --model=User --validation`