code: func (Actor) CommandInfos(commandList interface{}) map[string]CommandInfo {
  	handler := reflect.TypeOf(commandList)
  
  	infos := make(map[string]CommandInfo, handler.NumField())
  	for i := 0; i < handler.NumField(); i++ {
  		fieldTag := handler.Field(i).Tag
  		commandName := fieldTag.Get("command")
  		infos[commandName] = CommandInfo{
  			Name:        commandName,
  			Description: fieldTag.Get("description"),
  			Alias:       fieldTag.Get("alias"),
  		}
  	}
  
  	return infos
  }
docs: // CommandInfos returns a slice of CommandInfo that only fills in
  // the Name and Description for all the commands in commandList