Add "how to use or usage" in README.md

[Gujarats]

I think it is a good think to add this the usage on the README file. To make user understand faster.

[karuppiah7890]

@caarlos0 How do I install godownloader ?

[caarlos0]

docs are: https://install.goreleaser.com/

Install | GoReleaser

[karuppiah7890]

I did check it, but I don't see how to install godownloader

…

On Mon, Sep 24, 2018, 6:32 PM Carlos Alexandro Becker < ***@***.***> wrote: docs are: https://install.goreleaser.com/ — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#58 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AMNw6HvsgljxuLnZI3OlhKhb6olDoLjCks5ueNfSgaJpZM4Sy7nO> .

[github-actions]

Stale issue message

[mavogel]

I guess we can add it to the tab once we integrate releasing with goreleaser here as well. But yes docs for installing are not present yet. I downloaded the binary manually as well ^^

[github-actions]

This issue seems be stale, will auto-close soon.