Add back-to-top scroll up button in readme

[T-Fathima]

Issue Description

I would like to add back-to-top scroll up at the end of the readme file for easier navigation in lengthy readme file.
@swaraj-das Could you assign it to me.

Checklist

• I have checked the existing issues.
• The changes don't break the code
• Please attach the screenshots and video of the development work once it is done

[github-actions]

Congratulations, @T-Fathima! 🎉 Thank you for creating your issue. Your contribution is greatly appreciated and we look forward to working with you to resolve the issue. Keep up the great work!

We will promptly review your changes and offer feedback. Keep up the excellent work! Kindly remember to check our contributing guidelines

[github-actions]

Hi there! This issue is still open. We are looking forward to your response.
Assignees: None

[github-actions]

Hi there! This issue is still open. We are looking forward to your response.
Assignees: None