Update README.md

[komal3120]

Move Contributing Guidelines to Bottom of README

Fixes #0000

Make sure these boxes are checked before your pull request (PR) is ready to be reviewed and merged. Thanks!

• [ ] PR is descriptively titled 📑 and links the original issue above 🔗
• [ ] tests pass -- look for a green checkbox ✔️ a few minutes after opening your PR
• [ ] code is in uniquely-named feature branch and has no merge conflicts 📁
• [ ] screenshots/GIFs are attached 📎 in case of UI updation
• [ ] ask @publiclab/reviewers for help, in a comment below

[welcome[bot]]

Thanks for opening this pull request! This space is protected by our Code of Conduct - and we're here to help. Dangerbot will test out your code and reply in a bit with some pointers and requests. There may be some errors, but don't worry! We'll work through them with you! 👍🎉😄
One thing that can help to get started is to make sure you've included a link back to the original issue you're solving, in the format fixes #0000 (for example). And to make sure the PR title describes what you're trying to do! (often it can be the same as the issue title) Thanks! 🙌
Then, you can say hello in our chatroom & share a link to this PR to get a review! 👋 ✅

[gitpod-io[bot]]

[welcome[bot]]

Congrats on merging your first pull request! 🙌🎉⚡️ Your code will likely be published to http://infragram.org in the next few days. Now that you've completed this, you can help someone else take their first step! See: Public Lab's coding community!