Update Dockerfile

Author: jimboid

docker/Dockerfile

@@ -18,7 +18,7 @@ RUN pip install mdtraj mdplus
 # Get workshop files and move them to jovyan directory.
 COPY --chown=1000:100 . .
 RUN mv utilities.py /opt/conda/lib/python3.12/site-packages/utilities.py && \
-    rm -r AUTHORS LICENSE README.md docker .git .github
+    rm -rf AUTHORS LICENSE README.md docker .git .github
 
 # Copy lab workspace
 COPY --chown=1000:100 docker/default-37a8.jupyterlab-workspace /home/jovyan/.jupyter/lab/workspaces/default-37a8.jupyterlab-workspace