README: link and image to f-droid nightly repo

README.md

 # Android App for card10
 
-[![pipeline status](https://git.card10.badge.events.ccc.de/Anon/donkey/badges/master/pipeline.svg)](https://git.card10.badge.events.ccc.de/Anon/donkey/pipelines)
+[![pipeline status](https://git.card10.badge.events.ccc.de/card10/donkey/badges/master/pipeline.svg)](https://git.card10.badge.events.ccc.de/card10/donkey/pipelines)
 
 ## Download
 
-Latest Build binary from ci here:
+Per F-Droid nightly repository:
 
-[Download Debug-Binary](https://git.card10.badge.events.ccc.de/Anon/donkey/-/jobs/artifacts/master/raw/app/build/outputs/apk/debug/app-debug.apk?inline=false&job=build)
+[![https://git.card10.badge.events.ccc.de/card10/donkey-nightly/raw/master/fdroid/repo](https://git.card10.badge.events.ccc.de/card10/donkey-nightly/raw/master/icon.png)](https://git.card10.badge.events.ccc.de/card10/donkey-nightly/raw/master/fdroid/repo)