Implement Merge Sort in C++

[shaileshthakur1]

Hey @Sar-taj107 , I noticed in sorting we have all the sorting implemented in java only, so i thought of intergrating another language c++ in there. Kindly assign this issue to me , i want to work on this.

[Sar-taj107]

sure @shaileshthakur1 thanks for showing your interest start contributing!