Fix action to build docs

Author: dalito

.github/workflows/merge.yml

@@ -55,7 +55,7 @@ jobs:
 
       - name: Build Sphinx documentation (website)
         run: |
-          sphinx-build --nitpicky --fail-on-warning --keep-going docs docs/_build
+          sphinx-build -b html --nitpicky --fail-on-warning --keep-going docs docs/_build/html
 
       - uses: actions/upload-pages-artifact@7b1f4a764d45c48632c6b24a0339c27f5614fb0b
         with: