[TASK] Update page type chapter (#5402)

* [TASK] Update page type chapter

Resolves: #5102
Releases: main, 13.4, 12.4

* Update Documentation/ApiOverview/PageTypes/Index.rst

---------

Co-authored-by: Stefan Frömken <123929835+sfroemkenjw@users.noreply.github.com>

Author: linawolf

Documentation/ApiOverview/PageTypes/Index.rst

@@ -1,15 +1,34 @@
-.. include:: /Includes.rst.txt
-.. index:: Page types
-.. _page-types:
+..  include:: /Includes.rst.txt
+..  index:: Page types
+..  _page-types:
+..  _page-types-intro:
 
 ==========
 Page types
 ==========
 
-.. toctree::
-   :maxdepth: 1
+TYPO3 organizes content using different **page types**, each serving a specific
+purpose. See also `Types of pages <https://docs.typo3.org/permalink/t3coreapi:list-of-page-types>`_.
 
-   Introduction
-   TypesOfPages
-   RedirectHeaders
-   CreateNewPageType
+Each page type serves a different function in TYPO3’s content hierarchy, making
+it easier to manage complex websites.
+
+..  figure:: /Images/ManualScreenshots/PageTypes/Overview.png
+    :alt: Screenshot of the page properties form with highlighted page type (field `doktype`) and the page tree with the page type icons
+
+    When creating a page, different page types are available at the top of the page tree. The page type can be edited in the page properties for existing pages.
+
+The predefined page types are defined as constants in
+:php:`\TYPO3\CMS\Core\Domain\Repository\PageRepository`.
+
+Additional page types can be registered in the
+:php:`\TYPO3\CMS\Core\DataHandling\PageDoktypeRegistry`, see also
+`Create new Page Type <https://docs.typo3.org/permalink/t3coreapi:page-types-example>`_.
+
+..  toctree::
+    :caption: Topics
+    :maxdepth: 1
+
+    TypesOfPages
+    RedirectHeaders
+    CreateNewPageType

Documentation/ApiOverview/PageTypes/Introduction.rst

@@ -1,8 +1,11 @@
-.. include:: /Includes.rst.txt
-.. index::
-   Redirect headers
-   Http; X-Redirect-By
-   Page types; Redirect headers
+:navigation-title: Redirect Headers
+
+..  include:: /Includes.rst.txt
+..  index::
+    Redirect headers
+    Http; X-Redirect-By
+    Page types; Redirect headers
+..  _page-types-redirect-header:
 
 ==================================================
 X-Redirect-By header for pages with redirect types