Added the feature to auto comment on pr merged

[suhanipaliwal]

Description

I have added auto-comment-on-pr-merge.yml in .github/workflows directory. This file will add the feature of auto commenting when a pr is merged.

Related Issue

Fixes #390

Checklist:

• [x] I have performed a self-review of my code
• [x] I have added/updated relevant documentation (if needed)
• [x] I have tested the changes locally and they function as expected
• [x] I have ensured my code follows the project's coding standards

[codewarnab]

can you do a pr to ur fork and add the screenshot here if auto comments or not