Note widget attribute on serializer field. Closes #836.

docs/tutorial/1-serialization.md

@@ -146,6 +146,8 @@ The first thing we need to get started on our Web API is provide a way of serial
 
 The first part of serializer class defines the fields that get serialized/deserialized.  The `restore_object` method defines how fully fledged instances get created when deserializing data.
 
+Notice that we can also use various attributes that would typcially be used on form fields, such as `widget=widgets.Testarea`.  These can be used to control how the serializer should render when displayed as an HTML form.
+
 We can actually also save ourselves some time by using the `ModelSerializer` class, as we'll see later, but for now we'll keep our serializer definition explicit.  
 
 ## Working with Serializers