Update README

README.md

@@ -1,15 +1,14 @@
 # go-zendesk
-[![Gitter](https://badges.gitter.im/terraform-provider-zendesk/Lobby.svg)](https://gitter.im/terraform-provider-zendesk/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
 [![Build Status](https://travis-ci.org/nukosuke/go-zendesk.svg?branch=master)](https://travis-ci.org/nukosuke/go-zendesk)
 [![Build status](https://ci.appveyor.com/api/projects/status/ce4p1mswjkdftv6o/branch/master?svg=true)](https://ci.appveyor.com/project/nukosuke/go-zendesk/branch/master)
 [![Coverage Status](https://coveralls.io/repos/github/nukosuke/go-zendesk/badge.svg?branch=master)](https://coveralls.io/github/nukosuke/go-zendesk?branch=master)
 [![Go Report Card](https://goreportcard.com/badge/github.com/nukosuke/go-zendesk)](https://goreportcard.com/report/github.com/nukosuke/go-zendesk)
-[![GoDoc](https://godoc.org/github.com/zenform/go-zendesk?status.svg)](https://godoc.org/github.com/zenform/go-zendesk)
+[![GoDoc](https://godoc.org/github.com/zenform/go-zendesk?status.svg)](https://pkg.go.dev/github.com/nukosuke/go-zendesk/zendesk)
 [![FOSSA Status](https://app.fossa.io/api/projects/git%2Bgithub.com%2Fnukosuke%2Fgo-zendesk.svg?type=shield)](https://app.fossa.io/projects/git%2Bgithub.com%2Fnukosuke%2Fgo-zendesk?ref=badge_shield)
 
 Zendesk API client library for Go
 
-- [Reference](https://godoc.org/github.com/nukosuke/go-zendesk)
+- [Reference](https://pkg.go.dev/github.com/nukosuke/go-zendesk/zendesk)
 
 ## Installation
 
@@ -48,6 +47,10 @@ func main() {
 }
 ```
 
+## Want to mock API?
+go-zendesk has a [mock package](https://pkg.go.dev/github.com/nukosuke/go-zendesk/zendesk/mock) generated by [golang/mock](https://github.com/golang/mock).  
+You can simulate the response from Zendesk API with it.
+
 ## Authors
 - [nukosuke](https://github.com/nukosuke)
 - [tamccall](https://github.com/tamccall)