add SimpleStorage smart contract

simple-storage/script/DeploySimpleStorage.s.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.19;
+
+import {Script} from "forge-std/Script.sol";
+import {SimpleStorage} from "../src/SimpleStorage.sol";
+
+contract DeploySimpleStorage is Script {
+	function run() external returns (SimpleStorage) {
+		vm.startBroadcast();
+		SimpleStorage simpleStorage = new SimpleStorage();
+		vm.stopBroadcast();
+		return simpleStorage;
+	}
+}