[TASK] Add end of life hint and remove unused content from Includes.r…

…st.txt (#403)

* [TASK] Add end of life hint

Releases: 11.5

* [TASK] Remove unused content from Includes.rst.txt

Documentation/Includes.rst.txt

@@ -1,34 +1,8 @@
-.. More information about this file:
-   https://docs.typo3.org/m/typo3/docs-how-to-document/main/en-us/GeneralConventions/FileStructure.html#includes-rst-txt
-
-.. ----------
-.. text roles
-.. ----------
-
-.. role:: aspect(emphasis)
-.. role:: bash(code)
-.. role:: html(code)
-.. role:: js(code)
-.. role:: php(code)
-.. role:: rst(code)
-.. role:: sep(strong)
-.. role:: sql(code)
-
-.. role:: tsconfig(code)
-   :class: typoscript
-
-.. role:: typoscript(code)
-.. role:: xml(code)
-   :class: html
-
-.. role:: yaml(code)
-
-.. default-role:: code
-
-.. ---------
-.. highlight
-.. ---------
-
-.. By default, code blocks use PHP syntax highlighting
-
-.. highlight:: php
+..  attention::
+    TYPO3 v11 has reached end-of-life as of October 15th 2024 and
+    is no longer being maintained. Use the version switcher on the top left of
+    this page to select documentation for a supported version of TYPO3.
+
+    Need more time before upgrading?
+    You can purchase Extended Long Term Support (ELTS) for TYPO3 v11 here:
+    `TYPO3 ELTS <https://typo3.com/services/extended-support-elts>`__.