Allow install via homebrew

[ccoVeille]

Having an homebrew tap is a good way to make your tool available for people who don't have/want to build it via go install.

https://github.com/Homebrew/brew/blob/master/docs/How-to-Create-and-Maintain-a-Tap.md

Howbrew also helps people to get the last version of the tool. While go install is one shot thing.

I tend to install all my golang tool with homebrew, so I'm notified when they are updated.

You are already using goreleaser, you could configure an homebrew tap and update it via goreleaser

https://goreleaser.com/customization/homebrew/#homebrew-taps

[mfridman]

Not a bad idea.