remove warning note

Co-authored-by: Dongdong Tian <seisman.info@gmail.com>

Author: noorbuchi

examples/tutorials/date_time_charts.py

@@ -3,15 +3,6 @@
 ========================
 
 Plotting datetime charts is handled by :meth:`pygmt.Figure.basemap`.
-
-.. note::
-
-    This tutorial assumes the use of a Python notebook, such as IPython or Jupyter Notebook.
-    To see the figures while using a Python script instead, use
-    ``fig.show(method="external")`` to display the figure in the default PDF viewer.
-
-    To save the figure, use ``fig.savefig("figname.pdf")`` where ``"figname.pdf"``
-    is the desired name and file extension for the saved figure.
 """
 # sphinx_gallery_thumbnail_number = 0