Update doc/source/getting_started/intro_tutorials/04_plotting.rst

Author: mroeschke

doc/source/getting_started/intro_tutorials/04_plotting.rst

@@ -32,7 +32,7 @@ How do I create plots in pandas?
     air_quality.head()
 
 .. note::
-    The ``index_col=0`` and ``parse_dates=True`` parameters passed to the ``read_csv`` function define 
+    The ``index_col=0`` and ``parse_dates=True`` parameters passed to the ``read_csv`` function define
     the first (0th) column as index of the resulting ``DataFrame`` and convert the dates in the column
     to :class:`Timestamp`  objects, respectively.