Add GitHub Workflows for Greetings, Auto-Labeling, and PR Merge Notifications

[samyak-aditya]

fixed #74
Description:
To enhance repository automation and streamline contributor engagement, let's add GitHub workflows for greeting new contributors, auto-labeling pull requests, and notifying contributors on successful PR merges.

Proposed Workflows:

1. Greetings Workflow: Automatically welcome new contributors with a personalized message on their first issue or PR, encouraging them to contribute further.
2. Auto-Labeling Workflow: Configure a workflow to apply labels based on PR or issue content, making it easier to categorize and manage tasks.
3. PR Merge Notification: Add a workflow to send a notification to contributors when a pull request is successfully merged, keeping them informed of project updates.

Benefits:
These workflows will improve contributor experience, enhance project organization, and ensure that all contributors stay informed, contributing to a smoother collaboration process.

[github-actions]

Hello and welcome! 😊
Thank you for submitting your first pull request! Your contributions help us grow and improve this project. We're excited to review your changes. If you need any help or guidance, feel free to reach out. Let's build something amazing together! 🌟

[github-actions]

🎉 Your pull request has been successfully merged! 🎉 Thank you for your contribution to our project. Your efforts are greatly appreciated. Keep up the fantastic work! 🚀

[visheshrwl]

Hey @samyak-aditya ! 👋

First off, I want to extend a huge thank you to all of you for your amazing contributions to this project! Your support and hard work mean a lot, and I truly appreciate everything you do. 🙏

I have a small favor to ask: if you think I’ve been helpful and supportive throughout your contributions, I would be honored if you could nominate me by filling out this form: Nominate me.

Your nomination would mean the world to me, and it’s a great way to help me continue supporting our awesome community. Thanks again for all the amazing work, and let's keep making great things happen! 🚀

Best,
Vishesh