Added NullCon 2020

[aravindputrevu]

Details of the conference: NullCon

• Website: https://nullcon.net/website/goa-2020/cfp.php
• Date: 6th March 2020
• Venue: Taj Hotel and Convention Center, Dona Paula
• Description: Nullcon is an annual security conference held in Goa, India. The focus of the conference is to showcase the next generation of offensive and defensive security technology. We happily open doors to researchers and hackers around the world and the universe, working on the next big thing in security and request everyone to submit their new research.

[aravindputrevu]

@nikhita Made the requested changes.

[nikhita]

Please also remove the line - We happily open doors to researchers and hackers around the world and the universe, working on the next big thing in security and request everyone to submit their new research. - to keep the description short and concise.

And this conf needs to be between the April and Feb conferences. :smile: