docs: how to use nft.storage with Unity

[yusefnapora]

There's now a working nft.storage API wrapper for Unity: https://ericvanderwal.github.io/nftstoragesample/

We should write docs for it! Here's a video overview https://www.youtube.com/watch?v=tDXDKWSzOos&t=1s

I haven't yet played with it, so we should plan a day or two of poking around when scoping the docs work.

[DeveloperAlly]

Additional info Video (Nervos) Video (Moralis) Deck Github