Add CII best practices checklist.

Author: raar1

README.md

@@ -3,6 +3,7 @@
 [![PyPI version](https://badge.fury.io/py/fairworkflows.svg)](https://badge.fury.io/py/fairworkflows)
 [![fair-software.eu](https://img.shields.io/badge/fair--software.eu-%E2%97%8F%20%20%E2%97%8F%20%20%E2%97%8F%20%20%E2%97%8F%20%20%E2%97%8B-yellow)](https://fair-software.eu)
 [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/fair-workflows/fairworkflows/main?filepath=examples%2Ffairworkflows-quick-start.ipynb)
+[![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/4804/badge)](https://bestpractices.coreinfrastructure.org/projects/4804)
 
 # ```fairworkflows``` python library
 `fairworkflows` is a high-level, user-friendly python library that supports the construction,