[DOCS] Add AfterFormDefinitionLoadedEvent to EXT:form documentation

Resolves: #102964
Resolves: https://github.com/TYPO3-Documentation/Changelog-To-Doc/issues/812
Related: #102865
Releases: main
Change-Id: Iadf24ef5589d9defb0d4060b52039dcd69b5ff5e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/82682


Tested-by: Benjamin Franzke <ben@bnf.dev>
Tested-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Benjamin Franzke <ben@bnf.dev>
Reviewed-by: Garvin Hicking <gh@faktor-e.de>

typo3/sysext/form/Documentation/D/FrontendRendering/Index.rst

@@ -1664,3 +1664,16 @@ Use the hook
    public function beforeRendering(\TYPO3\CMS\Form\Domain\Runtime\FormRuntime $formRuntime, \TYPO3\CMS\Form\Domain\Model\Renderable\RootRenderableInterface $renderable)
    {
    }
+
+
+.. _apireference-frontendrendering-runtimemanipulation-events:
+
+PSR-14 event
+^^^^^^^^^^^^
+
+The following PSR-14 event is available to extend the functionality:
+
+AfterFormDefinitionLoadedEvent
+++++++++++++++++++++++++++++++
+
+Modify loaded form definitions. :ref:`More details <t3coreapi:AfterFormDefinitionLoadedEvent>`

typo3/sysext/form/Documentation/I/Concepts/FrontendRendering/Index.rst

@@ -754,6 +754,7 @@ With the provided hooks, this ``FormElement`` can now be manipulated.
 
 ..  seealso::
     *   :ref:`Hooks for runtime manipulation <apireference-frontendrendering-runtimemanipulation-hooks>`
+    *   :ref:`PSR-14 events <apireference-frontendrendering-runtimemanipulation-events>`
 
 If you insist on your own implementation, the abstract class ``TYPO3\CMS\Form\Domain\Model\FormElements\AbstractFormElement``
 offers a perfect entry point. In addition, we recommend checking-out ``TYPO3\CMS\Form\Domain\Model\Renderable\AbstractRenderable``.