docs(readme): replace godoc with pkg (#3985)

* Update README.md

README.md

@@ -5,7 +5,7 @@
 [![Build Status](https://github.com/gin-gonic/gin/workflows/Run%20Tests/badge.svg?branch=master)](https://github.com/gin-gonic/gin/actions?query=branch%3Amaster)
 [![codecov](https://codecov.io/gh/gin-gonic/gin/branch/master/graph/badge.svg)](https://codecov.io/gh/gin-gonic/gin)
 [![Go Report Card](https://goreportcard.com/badge/github.com/gin-gonic/gin)](https://goreportcard.com/report/github.com/gin-gonic/gin)
-[![GoDoc](https://pkg.go.dev/badge/github.com/gin-gonic/gin?status.svg)](https://pkg.go.dev/github.com/gin-gonic/gin?tab=doc)
+[![Go Reference](https://pkg.go.dev/badge/github.com/gin-gonic/gin?status.svg)](https://pkg.go.dev/github.com/gin-gonic/gin?tab=doc)
 [![Sourcegraph](https://sourcegraph.com/github.com/gin-gonic/gin/-/badge.svg)](https://sourcegraph.com/github.com/gin-gonic/gin?badge)
 [![Open Source Helpers](https://www.codetriage.com/gin-gonic/gin/badges/users.svg)](https://www.codetriage.com/gin-gonic/gin)
 [![Release](https://img.shields.io/github/release/gin-gonic/gin.svg?style=flat-square)](https://github.com/gin-gonic/gin/releases)
@@ -90,7 +90,7 @@ A number of ready-to-run examples demonstrating various use cases of Gin are ava
 
 ## Documentation
 
-See the [API documentation on godoc.org](https://godoc.org/github.com/gin-gonic/gin).
+See the [API documentation on go.dev](https://pkg.go.dev/github.com/gin-gonic/gin).
 
 The documentation is also available on [gin-gonic.com](https://gin-gonic.com) in several languages: