add sphinx-design package

Author: ajnonaka

.github/workflows/docs.yml

@@ -19,7 +19,7 @@ jobs:
           .github/workflows/dependencies/documentation.sh
           echo "Installing python packages for docs..."
           python3 -m pip install --upgrade pip
-          python3 -m pip install sphinx sphinx_rtd_theme breathe sphinxcontrib.bibtex docutils sphinx-copybutton
+          python3 -m pip install sphinx sphinx_rtd_theme breathe sphinxcontrib.bibtex docutils sphinx-copybutton sphinx-design
 
       - name: Install and Build
         run: |