integrate goreleaser and update readme with installation instructions

[kishaningithub]

Fixes #12

Every time you tag a version, artifacts for mac, windows and linux get generated automagically :-)

Things to do before merge for automated publish of automated taps homebrew taps

• Create a new repository titled homebrew-tap in your account
• Create a personal access token with push access
• Configure it as a secret environment named GA_GORELEASER_TOKEN
• More info https://goreleaser.com/customization/homebrew/

[maaslalani]

Hey, thanks so much for this PR! I normally like to wait for a library to get popular enough to where publishing binaries makes sense (rather than pre-emptively publishing) and I don't think confetty needs automatic publishing.

Rather than a homebrew-tap, if a library gets enough traction to where it warrants automatic publishing I will for sure add goreleaser and publish to homebrew-core like I do with https://github.com/maaslalani/slides.

Again, I really appreciate the issue and PR! Thank you so much :)