Update api-providers.mdx: Add OnFinality (#1676)

approved to add as a hosted RPC provider

Author: Danielvul

docs/data/apis/api-providers.mdx

@@ -25,6 +25,7 @@ These providers allow access to the Futurenet, Testnet and Mainnet network.
 | [Obsrvr](https://www.withObsrvr.com/) | ❌ | ✅ | ✅ | ✅ | ✅ |
 | [GetBlock](https://getblock.io/nodes/xlm/) | ❌ | ❌ | ✅ | ❌ | ✅ |
 | [Nodies](https://nodies.org) | ❌ | ✅ | ✅ | ✅ | ✅ |
+| [OnFinality](https://onfinality.io/networks/stellar) | ❌ | ❌ | ✅ | ❌ | ✅ |
 
 \*_Blockdaemon, Validation Cloud, and Quicknode combine Horizon and RPC in the same endpoint._
 
@@ -45,3 +46,4 @@ These providers allow access to the Futurenet, Testnet and Mainnet network.
 | [SDF](http://www.stellar.org) | Futurenet | RPC: `https://rpc-futurenet.stellar.org` <br /> Horizon: `https://horizon-futurenet.stellar.org` |
 |  | Testnet | RPC: `https://soroban-testnet.stellar.org` <br /> Horizon: `https://horizon-testnet.stellar.org` |
 | [LOBSTR](https://lobstr.co) | Mainnet | Horizon: `https://horizon.stellar.lobstr.co` |
+| [OnFinality](https://onfinality.io/networks/stellar) | Mainnet | RPC: `https://stellar.api.onfinality.io/public` |