Follow-up from "Add wiper script to avoid ZD downloads clutter"

The following discussions from !1 (merged) should be addressed:

• @weimeng started a discussion: (+4 comments)

  How about using ARGV so this isn't hardcoded? Or use a constant so folks can configure their downloads directory?

• @weimeng started a discussion: (+1 comment)

  Purely as a matter of style and neatness, you might want to put everything into a class. Something like:

  class DownloadsWiper
    def initialize(args)
      @downloads_dir = args.first || (Dir.home + '/Downloads')
    end
  
    def run!
      delete
      archive
    end
  
    private
  
    def some_helper_methods
      (...)
    end
  
    def delete
      (...)
    end
  
    def archive
      (...)
    end
  end
  
  DownloadsWiper.new(ARGV).run!