Update readme for release.

Author: Tim Bruijnzeels

README.md

@@ -25,6 +25,14 @@ in this [blog post](https://blog.nlnetlabs.nl/testing-the-waters-with-krill/).
 
 # Changelog
 
+## 0.12.3 'Sakura'
+
+This release contains some features which were cherry picked from the upcoming
+release (0.13.0) that will enable Publication Server operators to remove
+unwanted, surplus, files from their repository.
+
+For more details see: https://github.com/NLnetLabs/krill/pull/1022
+
 ## 0.12.2 'Dijkstra'
 
 This release fixes a locking issue that can affect a Krill Publication Server