Fix typo in eloquent-sortable.php (#168)

config/eloquent-sortable.php

@@ -8,7 +8,7 @@
 
     /*
      * Define if the models should sort when creating.
-     * When true, the package will automatically assign the highest order number to a new mode
+     * When true, the package will automatically assign the highest order number to a new model
      */
     'sort_when_creating' => true,
 ];