make output directory in action, since papermill needs it

.github/workflows/release.yml

@@ -32,6 +32,7 @@ jobs:
     - name: Run Jupyter Notebook
       run: |
         source .venv/bin/activate
+        mkdir -p output
         papermill omim_vs_orphanet_comparison.ipynb output/omim_vs_orphanet_comparison_output.ipynb --log-output        
 
     - name: Get Date for Release Tag