clarify Jupyter-specific functionality

Author: tobyhodges

_episodes/06-loops-and-functions.md

@@ -399,7 +399,24 @@ contains the documentation for the function. It does nothing when the function
 is running and is therefore not necessary, but it is good practice to include
 docstrings as a reminder of what the code does. Docstrings in functions also
 become part of their 'official' documentation, and we can see them by typing
-a `?` (question mark) after the function name:
+`help(function_name)`:
+
+~~~
+help(one_year_csv_writer)
+~~~
+{: .language-python }
+
+~~~
+Help on function one_year_csv_writer in module __main__:
+
+one_year_csv_writer(this_year, all_data)
+    Writes a csv file for data from a given year.
+    this_year -- year for which data is extracted
+    all_data -- DataFrame with multi-year data
+~~~
+{: .output }
+
+ Or, when working in the Jupyter environment, adding a `?` (question mark) after the function name:
 
 ~~~
 one_year_csv_writer?