docs: notice about custom parser

Author: JounQin

README.md

@@ -6,7 +6,6 @@
 [![David Dev](https://img.shields.io/david/dev/rx-ts/eslint-plugin-mdx.svg)](https://david-dm.org/rx-ts/eslint-plugin-mdx?type=dev)
 [![Conventional Commits](https://img.shields.io/badge/Conventional%20Commits-1.0.0-yellow.svg)](https://conventionalcommits.org)
 [![code style: prettier](https://img.shields.io/badge/code_style-prettier-ff69b4.svg)](https://github.com/prettier/prettier)
-[![License](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE)
 
 > [ESLint](https://eslint.org/) Parser/Plugin for [MDX](https://github.com/mdx-js/mdx)
 
@@ -44,3 +43,27 @@ npm i -D @rxts/eslint-plugin-mdx
    ```sh
    eslint . --ext js,mdx
    ```
+
+3. Custom parser for ES syntax is also supported:
+
+   ```json
+   {
+     "overrides": [
+       {
+         "files": ["*.mdx"],
+         "extends": ["plugin:@rxts/mdx/recommended"],
+         "parserOptions": {
+           "parser": "babel-eslint"
+         }
+       }
+     ]
+   }
+   ```
+
+## Changelog
+
+Detailed changes for each release are documented in [CHANGELOG.md](./CHANGELOG.md).
+
+## License
+
+[MIT](http://opensource.org/licenses/MIT)