upload artifact if not publish

.github/workflows/publish.yml

@@ -30,4 +30,10 @@ jobs:
         git config user.email "${GITHUB_ACTOR}@users.noreply.github.com"
         git remote set-url --push origin https://${GITHUB_ACTOR}:${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}
         make -O V=1 publish
+    - if: github.event_name != 'push' || github.ref != 'refs/heads/main'
+      name: artifact
+      uses: actions/upload-artifact@v2
+      with:
+        name: website
+        path: _site