Update rpcs.md

Add a new RPC provider to the list - GetBlock

Author: JoGetBlock

networks/mainnet/rpcs.md

@@ -36,6 +36,13 @@ Please note that publicly available hosted endpoints **only guarantee 2000 of th
     When using a lite-node, omit `/rpc/v1` from Glif’s WebSocket address.
 * [Glif documentation](https://hosting.glif.io/)
 
+* ## [GetBlock](https://getblock.io/nodes/fil/)
+
+GetBlock offers users access to shared and dedicated nodes with a simple pricing model. Developers can try out their services with a free plan, after which paid options are available for continued access.
+
+HTTPS: https://filecoin.getblock.io
+[GetBlock documentation](https://getblock.io/docs/getblock-explorer/get-started/)
+
 ## [NOWNodes](https://nownodes.io/)
 
 These nodes are available for free to users for the [first month](https://nownodes.io/pricing), after which the user will have to pay to maintain access.