add option to provide the RPC URL for a localhost network deployment

.env.example

@@ -1,3 +1,4 @@
 ETHERSCAN_API_KEY=<YOUR_ETHERSCAN_KEY>
 SEPOLIA_URL=https://eth-sepolia.alchemyapi.io/v2/<YOUR ALCHEMY KEY>
 PRIVATE_KEY=<YOUR_PRIVATE_KEY>
+RPC_PROVIDER=http://<RPC_IP>:<RPC_PORT>

hardhat.config.ts

@@ -12,7 +12,8 @@ import "hardhat-gas-reporter";
 import "solidity-docgen";
 
 dotenv.config();
-const { SEPOLIA_URL, PRIVATE_KEY, ETHERSCAN_API_KEY } = process.env;
+const { SEPOLIA_URL, PRIVATE_KEY, ETHERSCAN_API_KEY, RPC_PROVIDER } =
+  process.env;
 
 const getNetworkConfig = (): NetworksUserConfig | undefined => {
   if (SEPOLIA_URL && PRIVATE_KEY) {
@@ -34,6 +35,12 @@ const getNetworkConfig = (): NetworksUserConfig | undefined => {
         url: "http://localhost:8545",
       },
     };
+  } else if (RPC_PROVIDER) {
+    return {
+      localhost_integration: {
+        url: RPC_PROVIDER,
+      },
+    };
   }
   return undefined;
 };