Add 2023 Django Developers Survey banner (#1405)

* Add 2023 Django Developers Survey banner

* [pre-commit.ci] auto fixes from pre-commit.com hooks
---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

djangoproject/templates/base.html

@@ -69,8 +69,15 @@
         {% block header %}{% endblock %}
       </div>
     </div>
-    <div id="billboard">{% block billboard %}{% endblock %}</div>
-
+    <div id="billboard">{% block billboard %}
+      <div class="copy-banner" style="background: #44B78B;text-align:center;padding: 1em 3em;">
+        <div class="container">
+          <h1>Please take a few minutes to complete the
+            <a href="https://surveys.jetbrains.com/s3/django-developers-survey-2023" style="font-weight: bold;">Django Developers Survey 2023</a>.<br>Your feedback will help guide future efforts.
+          </h1>
+        </div>
+      </div>
+    {% endblock %}</div>
     <div class="container {% block layout_class %}{% endblock %}">
       <div role="main">