add screen recording to o1js README

[barriebyron]

A screen recording converted to a gif that shows how easy it is to download, scaffold a project and start building.

First iteration was completed in https://app.zenhub.com/workspaces/zkapps-product-eng-6130fedb3b0fc600123d8796/issues/gh/o1-labs/snarkyjs/291

Our updated o1js npm page looks so good https://www.npmjs.com/package/snarkyjs

Let's make it better!

Check out the Twitter/X post about the LambdaClass README for the bridge work https://x.com/class_lambda/status/1711457698129068125?s=20

[barriebyron]

Inspiration for awesome README, see https://www.appsmith.com/blog/write-a-great-readme

see README guidance https://github.com/o1-labs/docs2/wiki/README-files