def method_missing(*args)
      path = args.first.to_s
      if args.length == 1 && path.end_with?('.md')
        convert(path)
      else
        return super(*args)
      end
    end
def method_missing(*args)
      path = args.first.to_s
      if args.length == 1 && path.end_with?('.md')
        convert(path)
      else
        return super(*args)
      end
    end
Shorthand for `md2key convert *.md`