Feat: Auto Commenting feature for PR Merged

[Asymtode712]

Describe the feature

Currently, the greeting bot only autocomments on issue creation and when a PR raised.

To enhance our communication and acknowledgment process, we're implementing an auto-commenting feature for specific events within our project repository. This feature will automatically generate comments under the following circumstances:
PR Merged: Upon the successful merging of a pull request (PR), an auto-comment will be added to the corresponding issue, indicating that the PR has been merged and expressing gratitude to the contributor for their valuable contribution.

Add ScreenShots

Record

• I agree to follow this project's Code of Conduct
• I'm a GSSOC'24 contributor
• I want to work on this issue

[Asymtode712]

@XceeDesigns please assign me this issue under gssoc'24