Update package and eslint config

.eslintrc.js

+module.exports = {
+    "env": {
+        "browser": true,
+        "es2021": true,
+        "node": true,
+        "jquery": true
+    },
+    "extends": "eslint:recommended",
+    "parserOptions": {
+        "ecmaVersion": 12,
+        "sourceType": "module"
+    },
+    "rules": {
+        "indent": [
+            "error",
+            4
+        ],
+        /*"linebreak-style": [
+            "error",
+            "windows"
+        ],*/
+        "no-console": [
+            "off"
+        ],
+        "block-spacing": [
+            "error",
+            "always"
+        ],
+        "no-trailing-spaces": [
+            "error"
+        ],
+        "space-before-blocks": [
+            "error"
+        ],
+        "keyword-spacing": [
+            "error", {
+                "before": true,
+                "after": true
+            }
+        ]/*,
+        "quotes": [
+            "error",
+            "double"
+        ],
+        "semi": [
+            "error",
+            "always"
+        ]*/
+    },
+    "plugins": [
+        "html"
+    ],
+    "globals": {
+        "L": "readonly",
+        "d3": "readonly"
+    }
+};

package.json

@@ -17,5 +17,9 @@
     "morgan": "^1.10.0",
     "nodemon": "^2.0.7",
     "pg": "^8.6.0"
+  },
+  "devDependencies": {
+    "eslint": "^7.24.0",
+    "eslint-plugin-html": "^6.1.2"
   }
 }