Build Your Own C++ Calculator Project Addition

[RyanPrax]

Adds a C++ calculator project tutorial to line 43.

Checklist:

• [x ] My code follows the code style of this project.
• [ x] I have updated the documentation accordingly.
• [ x] I have read the CONTRIBUTING document.
• [ x] I have made checks to ensure URLs and other resources are valid

[anilyadavup54]

can i update your documentation

[RyanPrax]

@anilyadavup54 sure, go ahead