docs: Update userguide

Author: neznaika0

user_guide_src/source/changelogs/v4.6.4.rst

@@ -22,6 +22,8 @@ Message Changes
 Changes
 *******
 
+- **Config:** Added the ``synchronous`` key for ``Config\Database::$tests``. For SQLite3 driver only.
+
 ************
 Deprecations
 ************

user_guide_src/source/installation/upgrade_464.rst

@@ -44,7 +44,8 @@ and it is recommended that you merge the updated versions with your application:
 Config
 ------
 
-- @TODO
+- app/Config/Database.php
+    - Added the ``synchronous`` key for ``Config\Database::$tests``.
 
 All Changes
 ===========