pin docutils version for Sphinx

.github/workflows/documentation.yml

@@ -14,7 +14,7 @@ jobs:
 
     - name: Install Sphinx & Dependencies
       run: |
-        pip install sphinx sphinx_markdown_builder sphinx_rtd_theme sphinx-argparse m2r pandas bio
+        pip install sphinx sphinx_markdown_builder sphinx_rtd_theme sphinx-argparse m2r pandas bio "docutils==0.20"
         sudo apt-get install python3-distutils
     - name: Build Documentation
       working-directory: docs