Update CHANGELOG.rst

Author: sbillinge

CHANGELOG.rst

@@ -3,3 +3,20 @@ Release Notes
 =============
 
 .. current developments
+
+0.1.0
+=====
+
+**Added:**
+
+* Initial release of diffpy.snmf
+
+**Changed:**
+
+* Support Python version 3.12
+* Remove support for Python version 3.9
+
+**Fixed:**
+
+* Repo structure modified to the new diffpy standard
+* Code linting based on .pre-commit-config.yaml