Adopt ColPrac (#105)

Author: devmotion

README.md

@@ -4,6 +4,7 @@
 [![Dev](https://img.shields.io/badge/docs-dev-blue.svg)](https://JuliaDiff.github.io/AbstractDifferentiation.jl/dev)
 [![CI](https://github.com/JuliaDiff/AbstractDifferentiation.jl/actions/workflows/CI.yml/badge.svg?branch=master)](https://github.com/JuliaDiff/AbstractDifferentiation.jl/actions/workflows/CI.yml?query=branch%3Amaster)
 [![Coverage](https://codecov.io/gh/JuliaDiff/AbstractDifferentiation.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/JuliaDiff/AbstractDifferentiation.jl)
+[![ColPrac: Contributor's Guide on Collaborative Practices for Community Packages](https://img.shields.io/badge/ColPrac-Contributor's%20Guide-blueviolet)](https://github.com/SciML/ColPrac)
 
 ## Motivation