Move onchain logic to speperate dir.

onchain/script/Counter.s.sol

@@ -0,0 +1,19 @@
+/* // SPDX-License-Identifier: UNLICENSED */
+/* pragma solidity ^0.8.13; */
+
+/* import {Script, console} from "forge-std/Script.sol"; */
+/* import {Counter} from "../src/Counter.sol"; */
+
+/* contract CounterScript is Script { */
+/*     Counter public counter; */
+
+/*     function setUp() public {} */
+
+/*     function run() public { */
+/*         vm.startBroadcast(); */
+
+/*         counter = new Counter(); */
+
+/*         vm.stopBroadcast(); */
+/*     } */
+/* } */