Add eslint

eslint.config.js

@@ -0,0 +1,28 @@
+import js from "@eslint/js";
+import globals from "globals";
+import { defineConfig } from "eslint/config";
+import stylistic from "@stylistic/eslint-plugin";
+
+export default defineConfig([
+    {
+        files: ["**/*.{js,mjs,cjs}"],
+        plugins: { js, "@stylistic": stylistic },
+        extends: ["js/recommended"],
+        languageOptions: { globals: { ...globals.browser, ...globals.node } },
+        rules: {
+            "no-unused-vars": "off",
+            "no-undef": "off",
+            "no-var": "error",
+            "prefer-const": "error",
+            "no-redeclare": "error",
+            "@stylistic/semi": ["error", "always"],
+            "@stylistic/semi-spacing": ["error", { before: false, after: true }],
+            "@stylistic/no-tabs": "error",
+            "@stylistic/no-mixed-spaces-and-tabs": "error",
+            "@stylistic/quotes": ["error", "double"],
+            "@stylistic/object-curly-spacing": ["error", "always"],
+            "@stylistic/key-spacing": ["error", { beforeColon: false, afterColon: true }],
+            "@stylistic/keyword-spacing": ["error", { before: true, after: true }],
+        },
+    },
+]);