update RAEDME: add why april

README.md

@@ -3,12 +3,9 @@
 [![Build Status](https://travis-ci.org/cosven/april.svg?branch=master)](https://travis-ci.org/cosven/april)
 [![Coverage Status](https://coveralls.io/repos/github/cosven/april/badge.svg?branch=master)](https://coveralls.io/github/cosven/april?branch=master)
 
-lightweight & declarative model representation
-
-> `april` usually works along with serialization library, such as [marshmallow](http://marshmallow.readthedocs.io/en/latest/quickstart.html#deserializing-to-objects)
-
-**temporarily python3 only.**
+lightweight & declarative model representation.
 
+**model representation for human(maybe), temporarily python3 only.**
 
 ```python
 
@@ -20,7 +17,7 @@ UserModel({'name': 'Tom', 'age': 10})
 UserModel(name='Tom', age=10)
 ```
 
-**model representation for human**?
+[why april? -> see traditional ways of model definition](https://gist.github.com/cosven/0abb9a5bc52f3cc5109602e870ce709f)
 
 ## More Examples