Add hint about revealjs-ids to demo poster

Change-Id: I0ab9a0d7508faf85cd21a4540a32b293970ad7d3
diff --git a/inst/rmarkdown/templates/posterdown_ids/skeleton/skeleton.Rmd b/inst/rmarkdown/templates/posterdown_ids/skeleton/skeleton.Rmd
index ef09f6d..6cf6da1 100644
--- a/inst/rmarkdown/templates/posterdown_ids/skeleton/skeleton.Rmd
+++ b/inst/rmarkdown/templates/posterdown_ids/skeleton/skeleton.Rmd
@@ -45,7 +45,7 @@
 
 1. Easy to use reproducible poster design. [^1]
 2. Integration with R Markdown.
-3. Easy transition from `posterdown` ➝ `pagedown` report or manuscript documents [@R-pagedown].
+3. Easy transition from `posterdown` $➝$ `pagedown` report or manuscript documents [@R-pagedown] and [revealjs-ids](https://gitlab.ids-mannheim.de/ids/revealjs).
 
 [^1]:Footnotes are possible, too.