Check links with Zola (#938)

Author: samumantha

.github/workflows/build-upon-push-or-merge.yml

@@ -43,6 +43,9 @@ jobs:
            "https://github.com/getzola/zola/releases/download/v${ZOLA_VERSION}/zola-v${ZOLA_VERSION}-x86_64-unknown-linux-gnu.tar.gz" \
         | sudo tar xzf - -C /usr/local/bin
 
+    - name: Check for broken links
+      run: zola check
+
     - name: Generate HTML
       run: zola build