Add scripts for linting

package.json

@@ -18,6 +18,11 @@
     "url": "https://github.com/edward-shen/MMM-pages/issues"
   },
   "homepage": "https://github.com/edward-shen/MMM-pages#readme",
+  "scripts": {
+    "lint": "eslint .",
+    "lint:fix": "eslint . --fix",
+    "test": "npm run lint"
+  },
   "devDependencies": {
     "@eslint/js": "^9.16.0",
     "@stylistic/eslint-plugin": "^2.11.0",

readme.md

@@ -190,5 +190,13 @@ See also FAQ below.
 
   Please make an issue. Thanks!
 
+## Developer commands
+
+If you want to contribute to this poject, pleases use the following commands to maintain code quality:
+
+- `npm install` - Install development dependencies for linting.
+- `npm run lint` - Run linting checks.
+- `npm run lint:fix` - Fix linting issues. Please run this before committing.
+
 [mm]: https://github.com/MagicMirrorOrg/MagicMirror
 [page indicator]: https://github.com/edward-shen/MMM-page-indicator