Update changelog

Author: tarsius

CHANGELOG

@@ -1,4 +1,29 @@
 # -*- mode: org -*-
+* v0.9.0    UNRELEASED
+
+- Key descriptions (as returned by ~key-description~ and understood by
+  ~kbd~) are now the only key binding format understood by Transient.
+  Vectors are no longer supported.
+
+- Vectors are now preferred to identify a suffix or group in a menu by
+  coordinates.  It is still possible, but discouraged, to use a list.
+
+- The internal format used to store menu layouts has been improved.
+  The old format is still supported and translated on the fly when
+  encountered.  Instead of rely on that translation, users are advised
+  to recompile dependent packages after updating Transient to this
+  release.
+
+- Added new macro ~transient-define-group~, which defines one or more
+  groups of suffixes to be included in multiple menus.  Such included
+  groups are no longer immediately inlined when referenced in a menu
+  definition, which makes it possible for users to make changes to
+  included group and have those change affect all menus that include
+  them.
+
+- Added new macro ~transient-inline-group~, which inlines an included
+  group into a specific menu.
+
 * v0.8.8    2025-05-01
 
 - Added option ~transient-common-command-prefix~ to allow using a key