complete section on troubleshooting the installation

Author: danagilliann

CONTRIBUTING.rst

@@ -82,7 +82,7 @@ running other instances of Jupyter Notebook. You can try the following steps:
 1. Uninstall all instances of the notebook package. These include any installations you made using
    pip or conda
 2. Run ``python3 -m pip install -e .`` in the notebook repository to install the notebook from there
-3. Run ``npm run build`` to make sure the Javascript
+3. Run ``npm run build`` to make sure the Javascript and CSS are updated and compiled
 4. Launch with ``python3 -m notebook --port 8989``, and check that the browser is pointing to ``localhost:8989``
    (rather than the default 8888). You don't necessarily have to launch with port 8989, as long as you use
    a port that is neither the default nor in use, then it should be fine.