fix: Migrate .eslintrc.js to flat format eslint.config.mjs

Author: mman

.eslintrc.js

@@ -0,0 +1,27 @@
+import { FlatCompat } from '@eslint/eslintrc'
+const compat = new FlatCompat()
+
+import eslintPluginLocal from './eslint-plugin-local/index.mjs'
+
+export default [
+  // standard,
+  ...compat.extends('eslint-config-standard'),
+  {
+    files: ['**/**.js', '**/**.mjs'],
+    languageOptions: {
+      sourceType: 'module',
+      ecmaVersion: 'latest',
+    },
+    plugins: { 'local': eslintPluginLocal },
+    rules: {
+      /*
+        This is inserted to make this compatible with prettier.
+        Once https://github.com/prettier/prettier/issues/3845 and https://github.com/prettier/prettier/issues/3847 are solved this might be not needed any more.
+      */
+      'space-before-function-paren': 0,
+      curly: [2, 'all'],
+      'local/no-big-int': 'error',
+    },
+  },
+]
+