include plot script restructuring

mlair/plotting/data_insight_plotting.py

@@ -467,6 +467,7 @@ class PlotPeriodogram(AbstractPlotClass):  # pragma: no cover
         not compatible with any custom data handler. Proven data handlers are `DefaultDataHandler`,
         `DataHandlerMixedSampling`, `DataHandlerMixedSamplingWithFilter`. To work properly, the data handler must have
         the attribute `.id_class._data`.
+
     """
 
     def __init__(self, generator: Dict[str, DataCollection], plot_folder: str = ".", plot_name="periodogram",