update docutils to slightly newer version

Signed-off-by: Dave Dykstra <[email protected]>

.github/workflows/pull_request.yml

@@ -34,10 +34,10 @@ jobs:
 
       - name: Install Sphinx
         run: |
-          # docutils==0.16 is a temporary downgrade to fix a compiling issue
+          # docutils==0.18 is a temporary downgrade to fix a compiling issue
           # see https://github.com/CrossNox/m2r2/issues/68
           # requiring docutils version <0.21
-          pip install --user --upgrade --upgrade-strategy eager docutils==0.16 setuptools sphinx sphinx-rtd-theme restructuredtext_lint rstcheck pygments m2r2
+          pip install --user --upgrade --upgrade-strategy eager docutils==0.18 setuptools sphinx sphinx-rtd-theme restructuredtext_lint rstcheck pygments m2r2
 
       - name: Lint rst
         run: |