docs: def ensure_source_package_dir(nb_path, pkg_name):
      """Ensure all of the important directories in a source package exist"""
  
      pkg_path = join(dirname(nb_path), pkg_name)
  
      makedirs(join(pkg_path,'notebooks'),exist_ok=True)
      makedirs(join(pkg_path, 'docs'), exist_ok=True)
  
      return pkg_path