Created Code for Day1 Challenge - FizzBuzz in C++

[swapnil-satpathy]

Please make sure you have done the following:

• [ ] Created a folder with the name of language you code inside /Day<n>/ directory (Where n is for nth day)
• [ ] Added your Codes
• [ ] Tested your codes
• [ ] Added credits (author and date) at the top of the code
• [ ] Updated README.md
• [ ] Added yourself as a contributor using all-contributors-cli