Add adapted docstring to "Data Container" section.

Author: uvchik

doc/modules.rst

@@ -72,14 +72,15 @@ power curve or power coefficient curve needed by the :py:class:`~.wind_turbine.W
 
 .. _create_input_types_label:
 
-Create Data Container
+Data Container
 =====================
 
-Create groups to be used as an input in classes und functions.
+Create data container to be used as an input in classes und functions.
 
 .. autosummary::
    :toctree: temp/
 
+   wind_turbine.WindTurbineGroup
    wind_turbine.WindTurbine.to_group
 
 .. _wind_farm_label:
@@ -245,4 +246,4 @@ TurbineClusterModelChain example
 The ``turbine_cluster_modelchain_example`` consists of the following functions
 as well as it uses functions of the ``modelchain_example``.
 
-.. include:: example_2.rst
+.. include:: example_2.rst

windpowerlib/wind_turbine.py

@@ -269,11 +269,24 @@ class WindTurbineGroup(NamedTuple('WindTurbineGroup', [
     """
     A simple data container to define more than one turbine of the same type.
     Use the :func:`~windpowerlib.wind_turbine.WindTurbine.to_group` method to
-    easily create a WindTurbineGroup from a :class:`~windpowerlib.wind_turbine.WindTurbine` object.
+    easily create a WindTurbineGroup from a
+    :class:`~windpowerlib.wind_turbine.WindTurbine` object.
+
+    Parameters
+    ----------
+    'wind_turbine' : WindTurbine
+        A WindTurbine object with all necessary attributes.
+    'number_of_turbines' : float
+        The number of turbines. The number is not restricted to integer values.
     """
     __slots__ = ()
 
 
+WindTurbineGroup.wind_turbine.__doc__ = ':class:`~windpowerlib.wind_farm.WindFarm`'
+WindTurbineGroup.number_of_turbines.__doc__ = (
+    'Number of turbines of type WindTurbine')
+
+
 def get_turbine_data_from_file(turbine_type, path):
     r"""
     Fetches turbine data from a csv file.