fix(docs): update JavaScript setup instructions to include globals for ESLint

Author: Rel1cx

apps/website/content/docs/getting-started/javascript.mdx

@@ -6,12 +6,13 @@ description: Getting started with JavaScript setup
 ## Install
 
 ```package-install copy
-npm install --save-dev eslint @eslint/js @eslint-react/eslint-plugin
+npm install --save-dev globals eslint @eslint/js @eslint-react/eslint-plugin
 ```
 
 ## Setup
 
 ```js title="eslint.config.js"
+import globals from "globals";
 import eslintJs from "@eslint/js";
 import eslintReact from "@eslint-react/eslint-plugin";
 import { defineConfig } from "eslint/config";
@@ -24,15 +25,16 @@ export default defineConfig([
       eslintReact.configs.recommended,
     ],
     languageOptions: {
+      globals: {
+        ...globals.browser
+      }
       parserOptions: {
         ecmaFeatures: {
           jsx: true,
         },
       },
     },
     rules: {
-      // Add `globals` if you need this rule
-      "no-undef": "off",
       // Put rules you want to override here
       "@eslint-react/prefer-shorthand-boolean": "warn",
     },