Move bokeh backend illustration to directory

This packages requires a specific environment that is incompatible
with the standard environment for this training.

Author: gjbex

source-code/pandas/README.md

@@ -22,6 +22,5 @@ easy to use.
 1. `patients.ipynb`: runninng example used in the Python slides.
 1. `patient_data.ipynb`: extended version of therunninng example used
     in the Python slides.
-1. `bokeh_plot.ipynb`: using Bokeh as a plotting beackdnd for pandas.
 1. `pipes.ipynb`: consolidating data processing using pipes.
 1. `screenshots`: screenshots made for the slides.

source-code/pandas/bokeh/README.md

@@ -0,0 +1,12 @@
+# Bokeh
+
+You can use Bokeh as a plotting backend for pandas.
+
+## What is it?
+
+1. `bokeh_plot.ipynb`: using Bokeh as a plotting beackdnd for pandas.
+1. `environment.yml`: conda environment required to run the notebook.
+1. `pandas_bokeh_linux64_conda_specs.txt`: conda environment specification.
+
+*Note:* currently (2023-03-22) the bokeh backend for pandas requires
+bokeh 2.x, and that has to be specified as an explicit dependency.