Taps and casks

[remo5000]

• It would be nice to cover most adding functionality, so obviously taps and casks are the next in line as a feature.
• The Homebrew CLI parser is tricky, and I've spent some time trying to not evaluate words as formulae (unsuccessfully). This is an issue because brew interprets alacritty in brew add alacritty as a formula, regardless of parser options.
• Suggestion: use a standard CLI parser like brew-services (maybe not directly using argv though) and use brew internals like Formulary to do formula checks in a separate function