update godoc address

README.md

@@ -1,7 +1,7 @@
 # Mir
 [![Build Status](https://api.travis-ci.com/alimy/mir.svg?branch=master)](https://travis-ci.com/alimy/mir)
 [![codecov](https://codecov.io/gh/alimy/mir/branch/master/graph/badge.svg)](https://codecov.io/gh/alimy/mir)
-[![GoDoc](https://godoc.org/github.com/alimy/mir?status.svg)](https://godoc.org/github.com/alimy/mir)
+[![GoDoc](https://godoc.org/github.com/alimy/mir?status.svg)](https://pkg.go.dev/github.com/alimy/mir/v2)
 
 Mir is used for register handler to http router(eg: [Gin](https://github.com/gin-gonic/gin), [Chi](https://github.com/go-chi/chi), [Echo](https://github.com/labstack/echo), [Iris](https://github.com/kataras/iris), [Macaron](https://github.com/go-macaron/macaron), [Mux](https://github.com/gorilla/mux), [httprouter](https://github.com/julienschmidt/httprouter))
  depends on struct tag string info that defined in logic object's struct type field.