update docs

Author: greg-rychlewski

lib/ecto/adapters/postgres.ex

@@ -120,8 +120,7 @@ defmodule Ecto.Adapters.Postgres do
   alongside Ecto, you must define a type module with your extensions.
   Create a new file anywhere in your application with the following:
 
-      Postgrex.Types.define(MyApp.PostgresTypes,
-                            [MyExtension.Foo, MyExtensionBar] ++ Ecto.Adapters.Postgres.extensions())
+      Postgrex.Types.define(MyApp.PostgresTypes, [MyExtension.Foo, MyExtensionBar])
 
   Once your type module is defined, you can configure the repository to use it: