Check that PRs have correctly ran the sidebar gen

.gitlab-ci/lint.yml

@@ -89,6 +89,14 @@ markdownlint:
   script:
     - markdownlint $(find . -name '*.md' | grep -vF './.git') --ignore docs/_sidebar.md --ignore contrib/dind/README.md
 
+generate-sidebar:
+  extends: .job
+  stage: unit-tests
+  tags: [light]
+  script:
+    - scripts/gen_docs_sidebar.sh
+    - git diff --exit-code
+
 check-readme-versions:
   stage: unit-tests
   tags: [light]