docs: def find_build_dir(path, build="_build"):
      """try to guess the build folder's location"""
      path = os.path.abspath(os.path.expanduser(path))
      contents = os.listdir(path)
      filtered_contents = [directory for directory in contents
                              if os.path.isdir(os.path.join(path, directory))]
  
      if build in filtered_contents:
          return os.path.join(path, build)
      else:
          if path == os.path.realpath("/"):
              return None
          else:
              return find_build_dir("{0}/..".format(path), build)