tune README

[bikbah]

$ go get github.com/joho/godotenv/cmd/godotenv
go get: installing executables with 'go get' in module mode is deprecated.
        Use 'go install pkg@version' instead.
        For more information, see https://golang.org/doc/go-get-install-deprecation
        or run 'go help get' or 'go help install'.

[luisdavim]

LGTM

[sanak]

@joho (CC: @luisdavim, @alexandear)
Could someone merge this ?

[alexandear]

Sorry, but I can't merge because have no write access.

[sanak]

@alexandear Okay, sorry for mentioning you. 🙇

[sanak]

@joho @luisdavim
Could you merge this ?

If you care about older go versions, adding the following condition may be possible, but I am not sure whether library mode also needs to be fixed.

• Deprecation of 'go get' for installing executables - The Go Programming Language

---

or if you want to use it as a bin command
go >= 1.17

go install github.com/joho/godotenv/cmd/godotenv@latest

go < 1.17

go get github.com/joho/godotenv/cmd/godotenv