feat: Add Hardhat config, MockERC20 and tests for Smart Contract

hardhat.config.ts

@@ -0,0 +1,22 @@
+import { HardhatUserConfig } from "hardhat/config";
+import "@nomicfoundation/hardhat-toolbox";
+
+const config: HardhatUserConfig = {
+  solidity: {
+    version: "0.8.20",
+    settings: {
+      optimizer: {
+        enabled: true,
+        runs: 200,
+      },
+    },
+  },
+  paths: {
+    sources: "./contracts",
+    tests: "./test",
+    cache: "./cache",
+    artifacts: "./artifacts"
+  },
+};
+
+export default config;