added sphinx-exercise to requirements.txt

README.md

@@ -5,7 +5,7 @@ Demonstration of an open textbook made with [Jupyter Books](https://jupyterbook.
 ## Installation
 To install jupyter books, use pip:
 pip install jupyter-book
-(For this demo we used version 0.13.0)
+(For this demo we used version 0.13.1; you may have to replace pip by pip3 on newer installs).
 
 ## Building a Jupyter Book
 To build a jupyter book, run:

requirements.txt

@@ -4,4 +4,5 @@ plotly
 scipy
 matplotlib
 myst_nb
+sphinx-exercise
 jupyterquiz