Correct handling of previews. (#580)

* Reference the SHA of the pull request HEAD in the checkout.

* Minor content change to validate previews.

Author: freakboy3742

.github/workflows/ci.yml

@@ -9,7 +9,12 @@ jobs:
     runs-on: ubuntu-latest
     if: contains(github.event.pull_request.labels.*.name, 'preview')
     steps:
-      - uses: actions/checkout@v4
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+          fetch-depth: 0
+
       - name: Set up Python
         uses: actions/setup-python@v5
         with:

content/news/events/djangocon-us-2017-sprints/contents.lr

@@ -1,4 +1,4 @@
-title: DjangoCon US 2017 Sprints
+title: DjangoCon US 2017
 ---
 date: 2017-08-17
 ---