Add Ruby sample code and How to run them

[aashutoshrathi]

This issue is about Adding Ruby Sample codes and how to run.

• [ ] Issue Title is in form Algo/DS Name [Language].
• [x] I searched or browsed the repo’s other issues to ensure this is not a duplicate.
• [ ] This Algo/DS is worth adding to this repository.
• [ ] Assign this issue to me (I want to work on this).
  • [ ] I ensure that I am not already assigned to 2 or more issues.
• [ ] I will send my PR only after I'm assigned to this issue by any maintainer.
• [ ] I understand that I will be unassigned from this issue if I fail to send a PR for this within a week.

[lalitmee]

Hey guys, I can try to do this. :innocent: Simply I have to add steps to run ruby scripts and a sample code in the contributing guidelines. Am I right? :thinking: