[FEATURE] Document the :changelog: option of the version directives

Documentation/Reference/ReStructuredText/Content/Versions.rst

@@ -123,3 +123,59 @@ Find a changelog entry's permalink from its own
 `.. _<type>-<issue>-<timestamp>:` anchor, for example in the "Added files"
 section of the corresponding `Changelog-To-Doc <https://github.com/TYPO3-Documentation/Changelog-To-Doc>`__
 issue.
+
+..  _rest-versions-changelog-option:
+
+Linking the changelog entry with :rst:`:changelog:`
+===================================================
+
+The examples above write the changelog permalink by hand into the
+directive body. The three directives also accept a :rst:`:changelog:`
+option, which renders the link in the version badge itself and resolves
+the entry through the changelog inventory:
+
+..  code-block:: rst
+
+    ..  versionchanged:: 14.0
+        :changelog: feature-107628-1729026000
+
+        Most modules have been moved from :guilabel:`System` to
+        :guilabel:`Administration`.
+
+The link text is the title of the entry the option resolves to, so it
+reads the same as a hand-written permalink does today, without having to
+copy the title and the URL. An entry that does not exist produces a build
+warning and the unresolved-reference marker instead of a link that leads
+nowhere, which a hand-written permalink cannot do.
+
+The entry can be addressed in three ways:
+
+..  code-block:: rst
+
+    ..  TYPO3 Core: the changelog entry identifier on its own
+    ..  versionchanged:: 14.0
+        :changelog: feature-107628-1729026000
+
+    ..  Another manual: its interlink shortcode, then the entry anchor
+    ..  versionchanged:: 2.0
+        :changelog: acme/acme-blog:changes-2-0-0
+
+    ..  This manual's own changelog: the short "#anchor" form
+    ..  versionchanged:: 2.1
+        :changelog: #changes-2-1-0
+
+Where the resolved title does not describe the change - an extension
+whose whole changelog page carries a single label, for instance - give
+the text explicitly, in the same embedded form every other reference
+uses:
+
+..  code-block:: rst
+
+    ..  versionchanged:: 2.0
+        :changelog: Renaming the teaser field <acme/acme-blog:changelog>
+
+        The teaser field was renamed; see the changelog entry for the
+        migration.
+
+The entry itself is always a single token; only a text you supply may
+contain spaces.