Update contribution guide

[Achanandhi-M]

What has changed?

Please include a summary of the change.

I have updated the contribution guide and also removed unnecessary changes

Type of change

• [x] Bug fix (non-breaking change which fixes an issue).
• [x] Documentation update (if none of the other choices apply).

How Has This Been Tested?

Checklist:

• [x] My code follows the style guidelines of this project.
• [x] I have performed a self-review of my own code.