def init(part, extension="css")
      if (extension.eql?("css") || extension.eql?("scss"))
        Richcss::Generators::PartTemplate.start([part, extension])
      else
        puts "Only support css or scss extension, default is css"
      end
    end
def init(part, extension="css")
      if (extension.eql?("css") || extension.eql?("scss"))
        Richcss::Generators::PartTemplate.start([part, extension])
      else
        puts "Only support css or scss extension, default is css"
      end
    end
part_name
 |--- lib
 |    |--- elements
 |    |    |--- ...
 |    |--- box
 |    |    |--- ...
 |--- part_name.spec
 |--- README.md