Updated README.md

[therealsujitk]

• The last-update badge requires the field to be present in package.json. (Added a last-update field #191)
• A new preview GIF is to be made using the latest version.

[vatz88]

@therealsujitk hey until you have a new gif, can we add the old one back?

[vatz88]

Also, you only removed the ref in the readme, the file is still present in the code base

[therealsujitk]

Also, you only removed the ref in the readme, the file is still present in the code base

Yeah, I wasn't sure if you wanted to keep the old one until we make a new one, so I left it.

![Demo](/demo.gif)

This line will need to be added below This web application is a tool to visualize....

It'll be easier to commit directly to master rather than opening a new PR.

[vatz88]

I'm on my phone. Won't be on laptop until next week. It'd be nice if you can raise a PR. Nothing super urgent. I'll push it to master otherwise

[therealsujitk]

@vatz88 alright, will do!