[#1,#10] Add dependencies for 'yarn lint:sol' command

.solhint.json

@@ -0,0 +1,18 @@
+{
+  "extends": "solhint:recommended",
+  "plugins": ["prettier"],
+  "rules": {
+      "compiler-version": "off",
+      "func-visibility": [
+          "warn",
+          {
+              "ignoreConstructors": true
+          }
+      ],
+      "prettier/prettier": "error",
+      "not-rely-on-time": "off",
+      "reason-string": "off",
+      "no-empty-blocks": "off",
+      "avoid-low-level-calls": "off"
+  }
+}

package.json

@@ -26,6 +26,8 @@
     "hardhat-gas-reporter": "^1.0.8",
     "prettier": "^2.8.8",
     "prettier-plugin-solidity": "^1.1.3",
+    "solhint": "^3.4.1",
+    "solhint-plugin-prettier": "^0.0.5",
     "solidity-coverage": "^0.8.0",
     "ts-node": ">=8.0.0",
     "typechain": "^8.1.0",