Improve instance attributes explanation

Author: braboj

examples/08_classes/class_instance_attributes.py

@@ -1,3 +1,8 @@
+# Define and access instance attributes
+# ------------------------------------------------------------------------------
+# Instance attributes are defined in the __init__ method. They store data
+# unique to each object and can be accessed through the instance of the class.
+
 class Person(object):
 
     def __init__(self):