Web application for displaying leaderboard

[Vishalsh]

1. The PR adds the UI of the application which right now reads the dummy data from the data.json and refetches it after each 10sec.
2. The application uses vanilla javascript to fetch and simple HTML and CSS to display the data.
3. After the api is ready, change URL in the index.js to point to the actual end point.
4. Change INTERVAL in index.js to change the time after which the data needs to be refetched.
5. Please remove the dummy images once api is integrated with UI.

Checklist

• [x] Have you followed the guidelines for contributing?
• [x] Have you checked that there aren't other open pull requests for the same feature you're adding?
• [ ] Have you run tests (pipenv run pytest) before sending this PR?
• [ ] Have you run linting (./lint.sh) before sending this PR?

[javatarz]

Thanks @Vishalsh. I'm almost done with the API for this. I'll make the changes required to do the integration :)