docs: add changelog and upgrade

Author: kenjis

user_guide_src/source/changelogs/v4.4.4.rst

@@ -14,6 +14,12 @@ Release Date: Unreleased
 BREAKING
 ********
 
+Validation rules matches and differs
+====================================
+
+Bugs have been fixed in the case where ``matches`` and ``differs`` in the Strict
+and Traditional rules validate data of non-string types.
+
 ***************
 Message Changes
 ***************

user_guide_src/source/installation/upgrade_444.rst

@@ -20,6 +20,17 @@ Mandatory File Changes
 Breaking Changes
 ****************
 
+Validation rules matches and differs
+====================================
+
+Because bugs have been fixed in the case where ``matches`` and ``differs`` in
+the Strict and Traditional rules validate data of non-string types, if you are
+using these rules and validate non-string data, the validation results might be
+changed (fixed).
+
+Note that Traditional Rules should not be used to validate data that is not a
+string.
+
 *********************
 Breaking Enhancements
 *********************