added Sarthak Kundra to graduation list

[sarthakkundra]

Application to the Class of 2022🎓

Checklist ✅

• [x] I have read the instructions on the README file before submitting my application.
• [x] I made my submission by creating a folder on the _data folder and followed the naming convention mentioned in the instructions (<username>) and markdown file.
• [x] I have submitted a swag shipping form.
• [x] I have used the Markdown file template to add my information to the Year Book.
• [x] I understand that a reviewer will merge my pull request after examining it or ask for changes in case needed.
• [x] I understand I should not tag or add a reviewer to this Pull Request.
• [x] I have added the event to my Calendar.