Add support for installing with Homebrew

[ross-paypay]

Localstack can be installed with Homebrew (this formula).
It would be nice if we could also installed the awscli-local with Homebrew so we only need to use 1 package manager

[alexrashed]

We just recently created our own Homebrew tap with binary builds of the CLI: https://github.com/localstack/homebrew-tap
You can use this tap with brew install localstack/tap/localstack-cli.

However, we currently do not maintain any homebrew taps from our python packages.
The formula you referenced is community-maintained by the Homebrew community itself (which is awesome!).
There is already an awscli formulae in the community repo, and their processes seem to be heavily automated. It would be great if we could get a community formulae out there. However, I'm not 100% sure how the process of proposing new formulae works to be honest.

Otherwise, we could try to create our own formulae in https://github.com/localstack/homebrew-tap, with an action to automatically update the formulae on new releases of awslocal on PyPi.