new_file： numerical_methods/Monte_Carlo_simulation_PI.cpp

[Chuan1937]

Description of Change

Checklist

• [ x] Added description of change
• [x ] Added file name matches File name guidelines
• [x ] Added tests and example, test must pass
• [ x] Added documentation so that the program is self-explanatory and educational - Doxygen guidelines
• [ x] Relevant documentation/comments is changed or added
• [ x] PR title follows semantic commit guidelines
• [x ] Search previous suggestions before making a new one, as yours may be a duplicate.
• [ x] I acknowledge that all my contributions will be made under the project's license.

Notes:

[mjk22071998]

Please add one algorithm per Pull Request