Add the contribution.md file

[mayank29malhotra]

Description (Proposed Changes)

(Please try to mention in bullet points.)

-Added CONTRIBUTIONS.md to the project to outline the guidelines for contributing to the repository.

-Included sections on code style, commit messages, and pull request procedures in the CONTRIBUTIONS.md

Link to the issue :

(Add link of the issue you have proposed changes to)

• Link :
  Improve Contribution Guidelines #590
  Improve Contribution Guidelines #590

Tests

Please make sure to add tests when implementing new features.
Not relevant

Checklist

Please check that the PR fulfills all requirements listed below by checking the relevant checkboxes ([x]). This will ensure a smooth and quick review process.

• Set a 100 character limit in your editor/IDE to avoid white space diffs in the PR
• Tests for the changes have been added (for bug fixes / features)
• Added yourself to AUTHORS.md
• Updated/added relevant documentation (doc comments with ///).
• Added relevant reviewers.