docs: add changelog and note

Author: kenjis

user_guide_src/source/changelogs/v4.2.2.rst

@@ -18,11 +18,6 @@ BREAKING
 - A bug that caused pages to be cached before after filters were executed when using page caching has been fixed. Adding response headers or changing the response body in after filters now caches them correctly.
 - Due to a bug fix, now :php:func:`random_string` with the first parameter ``'crypto'`` throws ``InvalidArgumentException`` if the second parameter ``$len`` is an odd number.
 
-Enhancements
-************
-
-none.
-
 Changes
 *******
 

user_guide_src/source/changelogs/v4.2.3.rst

@@ -17,7 +17,7 @@ none.
 Enhancements
 ************
 
-none.
+- Now ``Security::generateHash()`` is public, and can be used to regenerate CSRF token manually when ``Config\Security::$regenerate`` is false.
 
 Changes
 *******

user_guide_src/source/libraries/security.rst

@@ -106,6 +106,9 @@ may alter this behavior by editing the following config parameter value in
 
 .. literalinclude:: security/004.php
 
+.. note:: Since v4.2.3, you can regenerate CSRF token manually with the
+    ``Security::generateHash()`` method.
+
 Redirection on Failure
 ----------------------