docs: def search_manager_from_config(config, **default_init):
      """Get a `SearchManager` instance dynamically based on config.
  
      `config` is a dictionary containing ``class`` and ``init`` keys as defined
      in :mod:`birding.config`.
      """
      manager_cls = import_name(config['class'], default_ns='birding.search')
      init = {}
      init.update(default_init)
      init.update(config['init'])
      manager = manager_cls(**init)
      return manager