NFT crawlers

[zomglings]

We should crawl information about available NFTs on Ethereum blockchain from sites like OpenSea and Nifty Gateway.

We will use this data to build an index of the NFT market.

The statistics we would like to incorporate into our index are:

1. Number of NFTs listed for sale on primary markets in a given time period (e.g. the past week)
2. Number of NFTs sold on primary markets in a given time period (e.g. the past week)
3. Amount of ETH spent on NFTs on primary markets in a given time period (e.g. the past week)
4. Number of NFTs listed for sale on secondary markets (e.g. auctions, OpenSea, etc.) in a given time period (e.g. the past week)
5. Number of NFTs sold on secondary markets (e.g. auctions, OpenSea, etc.) in a given time period (e.g. the past week)
6. Amount of ETH spent on NFTs on secondary markets in a given time period (e.g. the past week)
7. Amount of ETH earned by NFT creators in primary markets in a given time period (e.g. the past week)
8. Amount of ETH earned by NFT creators in secondary markets in a given time period (e.g. the past week)

Think about these statistics as you decide which labels to associate with crawled NFTs.

Hook into the labels + Ethereum addresses workflow that @kompotkot and @Yhtiyar built and are using for the Etherscan and CoinMarketCap crawls.

[zomglings]

@Andrei-Dolgolev : @Yhtiyar already started working on NFT crawl from Etherscan. Please sync up.