DOCS: update changelog

CHANGELOG.md

@@ -21,12 +21,15 @@
 
 * DEFAULTS:
     * Semi-Analytic Models
-        * New `Semi_Analytic_Models` instances now use galaxy merger-rates (instead of galaxy pair-fractions and merger-times) by default.  To use GPF+GMT SAMs, the user must pass in at least a GPF instance manually.
+        * `Semi_Analytic_Models` instances now use galaxy merger-rates (instead of galaxy pair-fractions and merger-times) by default.  To use GPF+GMT SAMs, the user must pass in at least a GPF instance manually.
 
 * BUGS:
     * Semi-Analytic Models
         * `Semi_Analytic_Model._dynamic_binary_number_at_fobs_inconsistent` was not checking for systems that had already coalesced.  Only effected GW-only evolution using the python version of the calculation.
 
+* Semi-Analytic Models
+    * Improve accuracy of dynamic binary number calculation for consistent evolution models.
+
 
 ## v1.5.2 - 2024/04/12