add eslint and add lint: npx eslint

Author: root

Makefile

@@ -3,4 +3,6 @@ install:
 brain-games:
 	node bin/brain-games.js
 publish:
-	npm publish --dry-run
+	npm publish --dry-run
+lint:
+	npx eslint

eslint.config.js

@@ -0,0 +1,12 @@
+import globals from "globals";
+import pluginJs from "@eslint/js";
+import pluginReact from "eslint-plugin-react";
+
+
+/** @type {import('eslint').Linter.Config[]} */
+export default [
+  {files: ["**/*.{js,mjs,cjs,jsx}"]},
+  {languageOptions: { globals: globals.browser }},
+  pluginJs.configs.recommended,
+  pluginReact.configs.flat.recommended,
+];