Improve Formatting and Code Quality (#934)

* Improved Formatting of basic_maths.py

- Added docstrings.
- Improved whitespace formatting.
- Renamed functions to match snake_case.

* Improved Formatting of factorial_python.py

- Added docstrings.
- Improved whitespace formatting.
- Renamed constants to match UPPER_CASE.

* Improved Formatting of factorial_recursive.py

- Improved whitespace formatting to meet PyLint standards.

* Improved Code to Conform to PyLint

- Renamed `max` to `max_num` to avoid redefining built-in 'max' [pylint]
- Removed unnecessary parens after 'while' keyword [pylint]

* Improved Formatting of factorial_recursive.py

- Added docstrings.
- Improved whitespace formatting.