Add Day 4 content

[Antiquely3059]

Select the Day of Content

Day 4

What information is missing?

Constants in C++

TASK:

What is Constants in C++?
How to Declare Constants in C++?
How to Define Constants in C++?
How to Use Constants in C++?
What are the Advantages of Constants in C++?
Best Practices for Using Constants in C++.
Examples of Constants in C++.

I would like to add the content for the above.

[github-actions]

Thank you for creating this issue! We'll look into it as soon as possible. Your contributions are highly appreciated! 😊

[subhadipbhowmik]

For sure. Keep working on it.