fix: ESM-specific configuration bugs (#445)

Author: ehmicky

.eslintrc_esm.cjs

@@ -8,6 +8,7 @@ const baseEslintrc = require('./.eslintrc.cjs')
 module.exports = {
   ...baseEslintrc,
   parserOptions: {
+    ...baseEslintrc.parserOptions,
     sourceType: 'module',
   },
   rules: {

package.json

@@ -4,7 +4,7 @@
   "type": "commonjs",
   "exports": {
     ".": "./.eslintrc.cjs",
-    "./esm": "./.eslintrc_esm.cjs",
+    "./.eslintrc_esm.cjs": "./.eslintrc_esm.cjs",
     "./.prettierrc.json": "./.prettierrc.json"
   },
   "main": "./.eslintrc.cjs",