[Feature] Support groups

[spuder]

As a user with multiple laptops, I'd like to have 1 brewfile that can support multiple installation targets using groups
so that I can prevent unapproved apps from being installed on my work computer

Example

group :personal do
  cask "arduino-ide"
  cask "steam"
end


group :work do
  brew "git"
  cask "visual-studio-code"
end

Reference

https://bundler.io/guides/groups.html

[jacobbednarz]

this was recently discussed in #1315 and has a couple of ideas in there how you can achieve this today.