Fix link formatting in release note

Change-Id: I3d6a703f74a662ca28022fe44ca936c192c7e89e

releasenotes/notes/dib-host-image-4fe8b1bf078f2d27.yaml

@@ -4,4 +4,4 @@ features:
     Adds support for building overcloud root disk images directly with DIB
     rather than through Bifrost. This includes support for building multiple
     images, each with a different configuration. See `story 2002098
-    <https://storyboard.openstack.org/#!/story/2002098>` for details.
+    <https://storyboard.openstack.org/#!/story/2002098>`__ for details.