set_kth_bit

want to solve this algorithm in c++.
language:

* [x] C++
* [ ] C
* [ ] JAVA
* [ ] Python

Non-Code:

* [x] Add readme
* [ ] Add images

problem link: https://practice.geeksforgeeks.org/problems/set-kth-bit3724/1?page=1&status[]=unsolved&category[]=Bit%20Magic&sortBy=submissions

the task is to set Kth bit of a given number

Start with the linked GeeksforGeeks problem and inspect the repository’s existing C++ solution layout to find where this algorithm belongs. Done means the C++ solution and the requested README entry are added and consistent with nearby examples.

Written by the indexing model from the issue text.