Improving the documentation

[denissskhannn]

Problem:
The readme file doesn't specify for whom the information is provided, what level do you need to be and what do you need to know prior. The lessons themselves are a bit difficult to comprehend, especially for people who don't know about Python or OOP. Some lessons don't provide an explanation and just have code in them (like Lesson 6) .

Solution I propose:
I would like to add syntax highlighting for people to better understand the code. I would also like to add a bit more details to the lessons (more examples, less terminology, more simplifications, adding diagrams), so it would be easier for people who know Python but don't know OOP or people who know OOP but don't know how to implement it in Python.

I will follow up with a pull request shortly.

Thank you for you time!