fix(guide): simplify directory structure

guide/english/python/object-oriented-programming/classes/index.md

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+---
+title: Classes
+---
+
+## Classes
+
+A Class is a "blueprint" for creating objects: writing a class permits to describe attributes and behaviors commons to every instance of this class. 
+
+## Create a Class
+
+To define a class the keyword **class** is used, followed by the name defining the class and a colon. All the following lines (code describing attributes and behaviors/methods) - are indented as in a Python function. For example, to create a class named Person, we can write:
+
+`class Person:
+   <code describing attributes and behaviors/methods> `
+
+Class definitions must be executed before they have any effect.
+
+#### More Information:
+<!-- Please add any articles you think might be helpful to read before writing the article -->
+
+