Added solution for reverse a linked list

[alexishp80]

Pull Request Template

Description

Adding my solution to problem 'Reverse a linked list' in the data structures section of HackerRank. link: https://www.hackerrank.com/challenges/reverse-a-linked-list/problem The code is properly commented for understanding the solution. If running in the local machine make sure JDK is installed. No dependency if using an online Java compiler.

Fixes # (issue) The solution to a Hackerrank question.

How Has This Been Tested?

This solution has passed all tests on HackerRank.

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] Any dependent changes have been merged and published in downstream modules