testest with eslint 7, update config

Author: GrosSacASac

js/red-javascript-style-guide/package.json

@@ -1,6 +1,6 @@
 {
     "name": "eslint-config-red",
-    "version": "1.7.0",
+    "version": "1.7.1",
     "license": "CC0-1.0",
     "homepage": "https://github.com/GrosSacASac/JavaScript-Set-Up/tree/master/js/red-javascript-style-guide",
     "files": [

js/red-javascript-style-guide/readme.md

@@ -678,7 +678,7 @@ Avoid peerDependencies because they create more problems than they solve, instea
 
 ### Lint set-up
 
-Install eslint 6+ and eslint-red rules
+Install eslint and eslint-red rules
 
 ```
 npm i -D eslint eslint-config-red
@@ -690,18 +690,22 @@ Inside package.json
 "eslintConfig": {
     "extends": ["red"],
     "parserOptions": {
-      "ecmaVersion": 2020,
+      "ecmaVersion": 2021,
       "sourceType": "module",
       "ecmaFeatures": {}
     },
     "env": {
-      "es2020": true,  
-      "browser": true
+      "es2021": true,  
+      "browser": true,
+      "node": true,
+      "serviceworker": true,
     },
     "rules": {}
 }
 ```
 
+Below es2021, remove unused evnironment.
+
 If code is meant for other environments other than browser, [add them to "env"](https://eslint.org/docs/user-guide/configuring#specifying-environments)
 
 Inside package.json > scripts