code: func DiffActionSymbol(action plans.Action) string {
  	switch action {
  	case plans.DeleteThenCreate:
  		return "[red]-[reset]/[green]+[reset]"
  	case plans.CreateThenDelete:
  		return "[green]+[reset]/[red]-[reset]"
  	case plans.Create:
  		return "  [green]+[reset]"
  	case plans.Delete:
  		return "  [red]-[reset]"
  	case plans.Read:
  		return " [cyan]<=[reset]"
  	case plans.Update:
  		return "  [yellow]~[reset]"
  	default:
  		return "  ?"
  	}
  }
docs: // DiffActionSymbol returns a string that, once passed through a
  // colorstring.Colorize, will produce a result that can be written
  // to a terminal to produce a symbol made of three printable
  // characters, possibly interspersed with VT100 color codes.