docs: add changelogs/v4.4.0.rst

Author: kenjis

user_guide_src/source/changelogs/v4.4.0.rst

@@ -23,6 +23,10 @@ Behavior Changes
 Interface Changes
 =================
 
+.. note:: As long as you have not extended the relevant CodeIgniter core classes
+    or implemented these interfaces, all these changes are backward compatible
+    and require no intervention.
+
 Method Signature Changes
 ========================
 
@@ -70,6 +74,7 @@ Others
   ``product/15`` where ``15`` is an arbitrary number.
   See :ref:`controller-default-method-fallback` for details.
 - **Filters:** Now you can use Filter Arguments with :ref:`$filters property <filters-filters-filter-arguments>`.
+- **Error Handling:** Now you can use :ref:`custom-exception-handlers`.
 
 Message Changes
 ***************
@@ -83,6 +88,10 @@ Changes
 Deprecations
 ************
 
+- Many methods and properties in ``CodeIgniter\Debug\Exceptions`` are deprecated.
+  Because these methods have been moved to ``BaseExceptionHandler`` or
+  ``ExceptionHandler``.
+
 Bugs Fixed
 **********