Port title frame

Change-Id: I0b78db5eed0ac7dbe779aa84505aeb1faa187f77
diff --git a/examples/ids.Rmd b/examples/ids.Rmd
index cdd895d..adba99a 100644
--- a/examples/ids.Rmd
+++ b/examples/ids.Rmd
@@ -1,5 +1,6 @@
 ---
-title: "IDS theme for revealjs demo"
+title: "IDS theme for revealjs"
+subtitle: "a demo"
 author: Marc Kupietz
 institute: "IDS Mannheim"
 date: "Mannheim, 2024-01-01"