docs(admin): Add upgrade to 31 section

juliusknorr · juliusknorr · commit e1fae84df759 · 2024-08-28T16:49:21.000+02:00
Signed-off-by: Julius Härtl &lt;jus@bitgrid.net&gt;
diff --git a/admin_manual/release_notes/index.rst b/admin_manual/release_notes/index.rst
@@ -14,6 +14,7 @@ These sub pages will cover the most important changes in Nextcloud, as well as s
 .. toctree::
    :maxdepth: 1
 
+   upgrade_to_31.rst
    upgrade_to_30.rst
    upgrade_to_28.rst
    upgrade_to_27.rst
diff --git a/admin_manual/release_notes/upgrade_to_31.rst b/admin_manual/release_notes/upgrade_to_31.rst
@@ -0,0 +1,13 @@
+=======================
+Upgrade to Nextcloud 31
+=======================
+
+System requirements
+-------------------
+
+* PHP 8.1 is now deprecated but still supported.
+
+PHP configuration
+-----------------
+
+We have a new setup warning to check if the memory reserved for APCu is high enough. If you see this warning, you should increase the memory reserved for APCu. You can do this by increasing the value of the ``apc.shm_size`` directive in your ``php.ini`` file. It is generally advised to review this value and increase it if necessary depending on your instance size.
