updated changelog

CHANGELOG.md

 # Changelog
 All notable changes to this project will be documented in this file.
 
+## v2.3.0 -  2022-11-25  - new models and plots
+
+### general:
+* new model classes for ResNet and U-Net
+* new plots and variations of existing plots
+
+### new features:
+* new model classes: ResNet (#419), U-Net (#423)
+* seasonal mse stack plot (#422)
+* new aggregated and line versions of Time Evolution Plot (#424, #427)
+* box-and-whisker plots are created for all error metrics (#431)
+* new split and frequency distribution versions of box-and-whisker plots for error metrics (#425, #434)
+* new evaluation metric: mean error / bias (#430)
+* conditional quantiles are now available for all competitors too (#435)
+* new map plot showing mse at locations (#432)
+
+### technical:
+* speed up in model setup (#421)
+* bugfix for boundary trim in FIR filter (#418)
+* persistence is now calculated only on demand (#426)
+* block mse are stored locally in a file (#428)
+* fix issue with boolean variables not recognized by argparse (#417)
+* renaming of ahead labels (#436)
+
 ## v2.2.0 -  2022-08-16  - new data sources and python3.9
 
 ### general: