Update README.md

Author: zenthangplus

README.md

@@ -2,6 +2,7 @@
 
 [![run tests](https://github.com/zenthangplus/go-workerpool/actions/workflows/test.yml/badge.svg?branch=main)](https://github.com/zenthangplus/go-workerpool/actions/workflows/test.yml)
 [![codecov](https://codecov.io/gh/zenthangplus/go-workerpool/branch/main/graph/badge.svg)](https://codecov.io/gh/zenthangplus/go-workerpool)
+[![goreportcard](https://goreportcard.com/badge/github.com/zenthangplus/go-workerpool)](https://goreportcard.com/report/github.com/zenthangplus/go-workerpool)
 
 Inspired from Java Thread Pool, Go WorkerPool aims to control heavy Go Routines.