code: func MoveToSubdir(oldpath, subdir string) error {
  
  	infos, err := ioutil.ReadDir(oldpath)
  	if err != nil {
  		return err
  	}
  	for _, info := range infos {
  		if info.Name() != subdir {
  			oldName := filepath.Join(oldpath, info.Name())
  			newName := filepath.Join(oldpath, subdir, info.Name())
  			if err := os.Rename(oldName, newName); err != nil {
  				return err
  			}
  		}
  	}
  	return nil
  }
docs: // MoveToSubdir moves all contents of a directory to a subdirectory underneath the original path