feat: add change storage examples

contracts/Storage.sol

@@ -0,0 +1,15 @@
+// contracts/Box.sol
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+contract Storage {
+    mapping(uint256 => uint256) public globalExitRootMap;
+
+    function get(uint256 key) public view returns (uint256) {
+        return globalExitRootMap[key];
+    }
+
+    function set(uint256 key, uint256 value) public {
+        globalExitRootMap[key] = value;
+    }
+}

scripts/storage_slot.js

@@ -0,0 +1,51 @@
+// We require the Hardhat Runtime Environment explicitly here. This is optional
+// but useful for running the script in a standalone fashion through `node <script>`.
+//
+// You can also run a script with `npx hardhat run <script>`. If you do that, Hardhat
+// will compile your contracts, add the Hardhat Runtime Environment's members to the
+// global scope, and execute the script.
+const hre = require("hardhat");
+
+async function main() {
+    const [owner] = await ethers.getSigners();
+    const storage = await hre.ethers.deployContract("Storage");
+    console.log('Deploying storage contact...');
+    storage.waitForDeployment();
+
+    let key = 1
+    let value = 10
+    await storage.connect(owner).set(key, value);
+
+    let getValue = await storage.connect(owner).get(1);
+    console.log("value: ", getValue);
+
+    let address = await storage.getAddress()
+
+    let slotP = 0
+    let abi = ethers.AbiCoder.defaultAbiCoder()
+    // uint256 and uint256 are mapping uint256 => uint256
+    let abiCode = abi.encode(["uint256", "uint256"], [key, slotP])
+    let slotId = ethers.keccak256(abiCode)
+    // 0xada5013122d395ba3c54772283fb069b10426056ef8ca54750cb9bb552a59e7d
+    console.log("slotId: ", slotId)
+    const slot = await network.provider.send("eth_getStorageAt", [
+        address, slotId
+      ]);
+
+    console.log("slot: ", slot)
+
+    let newValue = "0x0000000000000000000000000000000000000000000000000000000000000001"
+    await network.provider.send("hardhat_setStorageAt", [
+        address, slotId, newValue
+      ]);
+
+    let getNewValue = await storage.connect(owner).get(1);
+    console.log("newValue: ", getNewValue);
+}
+
+// We recommend this pattern to be able to use async/await everywhere
+// and properly handle errors.
+main().catch((error) => {
+    console.error(error);
+    process.exitCode = 1;
+});