[TASK] Add 10.4.x Changelog section

Resolves: #91166
Releases: master
Change-Id: Ief1dfff09aba275a11306693cf39ebc71992f5f9
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64301


Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Josef Glatz <josefglatz@gmail.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Josef Glatz <josefglatz@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>

typo3/sysext/core/Documentation/Changelog/10.4.x/Index.rst

+.. include:: ../../Includes.txt
+
+10.4.x Changes
+==============
+
+**Table of contents**
+
+.. contents::
+   :local:
+   :depth: 1
+
+
+Breaking Changes
+^^^^^^^^^^^^^^^^
+
+None since TYPO3 v10.0 release.
+
+.. attention::
+
+   After TYPO3 v10.0, only new functionality with a solid migration path can be added on top,
+   with aiming for as little as possible breaking changes after the initial v10.0 release on the way to LTS.
+
+Features
+^^^^^^^^
+
+.. toctree::
+   :maxdepth: 1
+   :titlesonly:
+   :glob:
+
+   Feature-*
+
+Deprecation
+^^^^^^^^^^^
+
+.. toctree::
+   :maxdepth: 1
+   :titlesonly:
+   :glob:
+
+   Deprecation-*
+
+Important
+^^^^^^^^^
+
+.. toctree::
+   :maxdepth: 1
+   :titlesonly:
+   :glob:
+
+   Important-*