add badge (doc) to README

Author: andreascaglioni

README.md

@@ -1,4 +1,6 @@
 [![CI](https://github.com/andreascaglioni/python-project-template/actions/workflows/tests.yml/badge.svg)](https://github.com/andreascaglioni/python-project-template/actions/workflows/tests.yml)
+[![Docs](https://github.com/andreascaglioni/python-project-template/actions/workflows/docs.yml/badge.svg)](https://github.com/andreascaglioni/python-project-template/actions/workflows/docs.yml)
+[![codecov](https://codecov.io/gh/andreascaglioni/python-project-template/branch/main/graph/badge.svg)](https://codecov.io/gh/andreascaglioni/python-project-template)
 [![PyPI Version](https://img.shields.io/pypi/v/python-project-template.svg)](https://pypi.org/project/python-project-template/)
 [![Python](https://img.shields.io/badge/python-3.8%2B-blue.svg)](https://www.python.org/)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)