docs(readme): update changelog

[skip ci]

Author: sanjayankur31

README.md

@@ -41,6 +41,38 @@ See https://docs.neuroml.org/ for an overview of the various NeuroML libraries.
 
 ## Changelog
 
+### version 0.5.6
+
+- documentation fixes to writer modules
+
+### version 0.5.5
+
+- update schema, changes for NML 2.3 release
+
+### version 0.5.4
+
+- use natsort to improve sorting of segments/groups when optimising
+
+### version 0.5.3
+
+- add links to schema documentation
+- move from legacy setup.py to pyproject.toml build system
+
+### version 0.5.2
+
+- explicitly depend on numpy
+
+### version 0.5.1
+
+- updates to GHA
+
+### version 0.5.0
+
+- enable CI on py3.11
+- fix to loaders
+- format code with black
+- add graph representation for morphology, and methods to calculate distances b/w segments
+
 ### version 0.4.1
 
 - add multiple cell builder utility functions