Add blockfrost Cardano (#2529)

README.md

@@ -325,6 +325,7 @@ API | Description | Auth | HTTPS | CORS |
 | [Block](https://www.block.io/docs/basic) | Bitcoin Payment, Wallet & Transaction Data | `apiKey` | Yes | Unknown |
 | [Blockchain](https://www.blockchain.com/api) | Bitcoin Payment, Wallet & Transaction Data | `apiKey` | Yes | Unknown |
 | [BlockFacts](https://blockfacts.io/) | Real-time crypto data from multiple exchanges via a single unified API, and much more | `apiKey` | Yes | Unknown |
+| [blockfrost Cardano](https://blockfrost.io/) | Interaction with the Cardano mainnet and several testnets | `apiKey` | Yes | Unknown |
 | [Bybit](https://bybit-exchange.github.io/docs/linear/#t-introduction) | Cryptocurrency data feed and algorithmic trading | `apiKey` | Yes | Unknown |
 | [CoinAPI](https://docs.coinapi.io/) | All Currency Exchanges integrate under a single api | `apiKey` | Yes | No |
 | [Coinbase](https://developers.coinbase.com) | Bitcoin, Bitcoin Cash, Litecoin and Ethereum Prices | `apiKey` | Yes | Unknown |