docs: add v2 go reference to readme

README.md

@@ -1,6 +1,7 @@
 [![][kong-logo]][kong-url]
 [![Build Status](https://github.com/kong/kubernetes-ingress-controller/workflows/Test/badge.svg)](https://github.com/kong/kubernetes-ingress-controller/actions?query=branch%3Amaster+event%3Apush)
-[![codecov](https://codecov.io/gh/Kong/kubernetes-ingress-controller/branch/main/graph/badge.svg?token=S1aqcXiGEo)](https://codecov.io/gh/Kong/kubernetes-ingress-controller)
+[![Go Reference](https://pkg.go.dev/badge/github.com/kong/kubernetes-ingress-controller/v2.svg)](https://pkg.go.dev/github.com/kong/kubernetes-ingress-controller/v2)
+[![Codecov](https://codecov.io/gh/Kong/kubernetes-ingress-controller/branch/main/graph/badge.svg?token=S1aqcXiGEo)](https://codecov.io/gh/Kong/kubernetes-ingress-controller)
 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://github.com/Kong/kong/blob/master/LICENSE)
 [![Twitter](https://img.shields.io/twitter/follow/thekonginc.svg?style=social&label=Follow)](https://twitter.com/intent/follow?screen_name=thekonginc)