Add blogdown::check_content diagnostic

Hopefully will show why draft posts are being published

Author: krivard

.github/workflows/blog.yaml

@@ -67,6 +67,9 @@ jobs:
       - name: Build site
         run: |
           npm run build:blog
+      - name: Check site
+        run: |
+          Rscript -e "blogdown::check_content()"
       - uses: actions/upload-artifact@v3
         with:
           name: blog