add func call in chapter 1.1

Change-Id: I82ee8135f93d9b57ccb34f3f429f8fccbd5d4fcb

Author: air82

Readme.md

@@ -122,13 +122,15 @@
 a = 1
 def fun(a):
     a = 2
+fun(a)
 print a  # 1
 ```
 
 ```python
 a = []
 def fun(a):
     a.append(1)
+fun(a)
 print a  # [1]
 ```