Merge pull request #770 from DougBurke/update-changelog

Update changelog

Changes.CIAO_scripts

@@ -1,4 +1,4 @@
-## 4.15.2 - April 2023
+## 4.15.2 - June 2023
 
 New scripts
 
@@ -19,12 +19,21 @@ Updated scripts
 
     Updated to change the matplotlib plotting backend if no DISPLAY is set.
 
+  convert_xspec_script
+
+    Improve compatability with XSPEC, as there is now support for
+    using XSPEC user models (using the --models option), initial
+    support for the MDEFINE command (not all cases are supported),
+    tweaks to handling of the NOTICE and IGNORE commands to handle
+    files that do not follow the OGIP standards, and improvements in
+    model parsing (so some scipts that used to produce invalid source
+    models will now work).
+
   convert_xspec_user_model
 
     Update to better support building with shared libraries on macOS.
 
-
-  correct_perioscope_drift
+  correct_periscope_drift
 
     Updated to change the matplotlib plotting backend if no DISPLAY is set.