docs: def discover_conf_py_directory(initial_dir):
      """Discover the directory containing the conf.py file.
  
      This function is useful for building stack docs since it will look in
      the current working directory and all parents.
  
      Parameters
      ----------
      initial_dir : `str`
          The inititial directory to search from. In practice, this is often the
          directory that the user is running the stack-docs CLI from.
  
      Returns
      -------
      root_dir : `str`
          The root documentation directory containing ``conf.py``.
  
      Raises
      ------
      FileNotFoundError
          Raised if a ``conf.py`` file is not found in the initial directory,
          or any parents.
      """
      # Create an absolute Path to work with
      initial_dir = pathlib.Path(initial_dir).resolve()
  
      # Search upwards until a conf.py is found
      try:
          return str(_search_parents(initial_dir))
      except FileNotFoundError:
          raise