Use our own artifact in Readme

Change-Id: Ie7f8c7cba21aad9854fe2a0528d5571d2378fb43
diff --git a/README.md b/README.md
index b85c899..0d62c13 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@
 
 |  `posterdown_ids` |
 |:------------------:|
-| [![](./images/ids_poster.svg)<!-- -->](./images/ids_poster.svg) |
+| [![](https://gitlab.ids-mannheim.de/ids/posterdown/-/jobs/artifacts/master/raw/target/skeleton_optimized.svg?job=build-job)<!-- -->](./inst/rmarkdown/templates/posterdown_ids/skeleton/skeleton.Rmd) |
 
 | `posterdown_html` | `posterdown_betterland` | `posterdown_betterport` |
 |:---------------:|:---------------------:|:---------------------:|