chore: format code and add prettier

package.json

@@ -6,7 +6,10 @@
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
     "dev": "nodemon ./app.js",
-    "start": "node ./app.js"
+    "start": "node ./app.js",
+    "lint:prettier": "prettier --check .",
+    "lint": "yarn lint:prettier",
+    "lintfix": "prettier --write --list-different ."
   },
   "author": "",
   "license": "MIT",
@@ -24,5 +27,8 @@
     "node-rsa": "^1.1.1",
     "nodemon": "^2.0.21",
     "serve-favicon": "^2.4.2"
+  },
+  "devDependencies": {
+    "prettier": "^2.8.4"
   }
 }