Add Merge Sort using Linked List

[VanshGarg06]

Problem Title : Merge Sort using Linked List

We can only do the Merge Sort to sort the linked list as it works on the recursive approach and could be useful to solve the problem. The Linked list will be sorted using the Merge Sort only and not other algorithm could be applied directly.

The Merge Sort is one of the most efficient and important sorting algorithm that could use the recursive approach to solve the problem.

Please assign this issue to me so that i could implement the problem in different programming languages. Please assign this issue to me under @Hacktoberfest and with necessary labels @hacktoberfest-accepted , @Hacktoberfest2025 and @Hacktoberfest.

[Priyanshu-2545]

“I would like to work on this issue. Please assign it to me under Hacktoberfest.”

[VanshGarg06]

This repo is not counting for hacktoberfest.