ci: add eslint flat config file

Author: cdzzy

eslint.config.js

@@ -0,0 +1,15 @@
+import js from '@eslint/js';
+
+export default [
+  js.configs.recommended,
+  {
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: 'module',
+    },
+    rules: {
+      'no-unused-vars': ['warn', { argsIgnorePattern: '^_' }],
+      'no-console': 'off',
+    },
+  },
+];