Deploy NFTs on Polygon

Based on a guide from Pinata
Understanding the relationship between NFT contract, asset files and metadata.

Notes:

• asset file and metadata.json file are uploaded separately.
• NFT (ERC721) contract references a uri that is pointing to the metadata.json. The metadata file then points to the asset file in its image key
• same process in ethereum or polygon, just switch network configurations.
• after deploying and updating uri, check NFT contract on polygonscan -> call tokenURI() -> get ipfs://QmQ3ayz3G45ztZR3L2s2Vjfcy9CmYr1kKpQmhhkXWYafDs -> get "image" attribute -> get asset file / folder