[libc++][doc] Fixes unwanted list nesting.

NOKEYCHECK=True
GitOrigin-RevId: b3d1142d09f17feacc74ee422375243e35bb32c8
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index b2bd071..f6bca74 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -63,11 +63,11 @@
   "heapsort with bounce" to reduce the number of comparisons, and rearranges
   elements using move-assignment instead of `swap`.
 
- - Libc++ now supports a variety of assertions that can be turned on to help catch
-   undefined behavior in user code. This new support is now separate from the old
-   (and incomplete) Debug Mode. Vendors can select whether the library they ship
-   should include assertions or not by default. For details, see
-   :ref:`the documentation <assertions-mode>` about this new feature.
+- Libc++ now supports a variety of assertions that can be turned on to help catch
+  undefined behavior in user code. This new support is now separate from the old
+  (and incomplete) Debug Mode. Vendors can select whether the library they ship
+  should include assertions or not by default. For details, see
+  :ref:`the documentation <assertions-mode>` about this new feature.
 
 API Changes
 -----------