[Backport 13.4] [DOCS] Document how the page tree can be changed

Documentation/ApiOverview/Backend/PageTree.rst

@@ -0,0 +1,42 @@
+:navigation-title: Page tree
+..  include:: /Includes.rst.txt
+..  _page-tree:
+
+==================================
+The page tree in the TYPO3 backend
+==================================
+
+The **page tree** is a hierarchical structure that represents pages and their
+subpages on a website, allowing editors and integrators to easily organize and
+manage content and navigation.
+
+It is displayed on the left of backend modules with
+:ref:`navigationComponent <t3coreapi:confval-backend-module-navigationcomponent>`
+set to `'@typo3/backend/tree/page-tree-element'`.
+
+Usage of the page tree is described in
+`Getting Started Tutorial, Page tree <https://docs.typo3.org/permalink/t3start:page-tree>`_.
+
+The page tree can also be navigated via `Keyboard commands (Tutorial for
+Editors) <https://docs.typo3.org/permalink/t3editors:keyboard-commands>`_.
+
+..  contents:: Table of contents
+
+..  _page-tree-events:
+
+PSR-14 events to influence the functionality of the page tree
+=============================================================
+
+:ref:`AfterPageTreeItemsPreparedEvent`
+    Allows prepared page tree items to be modified.
+:ref:`AfterRawPageRowPreparedEvent`
+    Allows to modify the populated properties of a page and children records
+    before the page is displayed in a page tree.
+
+..  _page-tree-tsconfig:
+
+TsConfig settings to influence the page tree
+============================================
+
+The rendering of the page tree can be influenced via user TsConfig
+:ref:`options.pageTree <t3tsref:confval-useroptions-pagetree>`.