Added Steem (#2581)

README.md

@@ -208,6 +208,7 @@ API | Description | Auth | HTTPS | CORS |
 | [Chainpoint](https://tierion.com/chainpoint/) | Chainpoint is a global network for anchoring data to the Bitcoin blockchain | No | Yes | Unknown |
 | [Covalent](https://www.covalenthq.com/docs/api/) | Multi-blockchain data aggregator platform | `apiKey` | Yes | Unknown |
 | [Nownodes](https://nownodes.io/) | Blockchain-as-a-service solution that provides high-quality connection via API | `apiKey` | Yes | Unknown |
+| [Steem](https://developers.steem.io/) | Blockchain-based blogging and social media website | No | No | No |
 | [The Graph](https://thegraph.com) | Indexing protocol for querying networks like Ethereum with GraphQL | No | Yes | Unknown |
 | [Walltime](https://walltime.info/api.html) | To retrieve Walltime's market info | No | Yes | Unknown |