Homebrew: add to Core repo

Sort of follow up to #607 It would be nice to eventually move to a simpler command since the product has matured and and releases are fewer. Something like `brew install tfswitch` in the near future. * 📝 https://docs.brew.sh/Acceptable-Casks * 🛠️ https://docs.brew.sh/Adding-Software-to-Homebrew#casks * https://docs.brew.sh/How-To-Open-a-Homebrew-Pull-Request (`brew bump-cask-pr <outdated_cask>`) * https://docs.brew.sh/Manpage#bump-cask-pr-options-cask * https://github.com/Homebrew/homebrew-cask/blob/master/CONTRIBUTING.md#updating-a-cask (`brew bump --open-pr <outdated_cask>`) * 🤖 CI/CD on-release automation: https://github.com/marketplace/actions/homebrew-bump-cask (https://github.com/macauley/action-homebrew-bump-cask) * 📌 Leave existing third-party tap automation for those who want faster iteration rather than waiting for the update to make it via the PR process in core Homebrew repo