Add a simple README.md to the sub template

sub/frontend_project/README.md

@@ -0,0 +1,55 @@
+[![Cookieplone Frontend Project CI](https://github.com/plone/cookieplone-templates/actions/workflows/frontend_addon.yml/badge.svg)](https://github.com/plone/cookieplone-templates/actions/workflows/frontend_addon.yml)
+[![Built with Cookiecutter](https://img.shields.io/badge/built%20with-Cookiecutter-ff69b4.svg?logo=cookiecutter)](https://github.com/plone/cookieplone-templates/)
+![GitHub](https://img.shields.io/github/license/plone/cookiecutter-plone)
+[![Black code style](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)
+
+# Cookieplone Frontend Project
+
+This is a sub-template -- used by other templates, in automated tests, and for OCI image generation -- accessible with **cookieplone** at the path `sub/frontend_project`.
+
+## Getting Started 🏁
+
+### Prerequisites
+
+- **pipx**: A handy tool for installing and running Python applications.
+
+### Installation Guide 🛠️
+
+1. **pipx**
+
+```shell
+pip install pipx
+```
+### Generate Your Frontend project 🎉
+
+```shell
+pipx run cookieplone sub/frontend_project --no_input __version_plone_volto=18.0.0-alpha.31
+```
+
+## Project Generation Options
+
+These are all the template options that will be prompted by the [Cookiecutter CLI](https://github.com/cookiecutter/cookiecutter) before generating your project.
+
+| Option                | Description                                                                                                                                          | Example                       |
+| --------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------- |
+| `title`  | Your project's human-readable name, capitals and spaces allowed.                                                                                     | **Frontend Project**                |
+| `author`              | This is you! The value goes into places like ``LICENSE``, ``package.json`` and such.                                                                     | **Our Company**               |
+| `email`               | The email address you want to identify yourself in the project.                                                                                      | **[email protected]**         |
+| `volto_version` | Volto version to be used. | **18.0.0-alpha.31**    |
+
+
+## Code Quality Assurance 🧐
+
+Your package comes equipped with linters to ensure code quality. Run the following to automatically format your code:
+
+```shell
+make format
+```
+
+## License 📜
+
+This project is licensed under the [MIT License](/LICENSE).
+
+## Let's Get Building! 🚀
+
+Happy coding!