Add 25.10 upgrade notes

Author: badlop

content/admin/upgrade/index.md

@@ -101,6 +101,7 @@ of the new ejabberd version if you need to update those tables yourself manually
 The corresponsing ugprade notes are available in the release notes of each release,
 and also available in the [Archive](../../archive/index.md) section:
 
+- [Upgrading from ejabberd 25.08 to 25.10](../../archive/25.10/upgrade.md)
 - [Upgrading from ejabberd 25.07 to 25.08](../../archive/25.08/upgrade.md)
 - [Upgrading from ejabberd 25.04 to 25.07](../../archive/25.07/upgrade.md)
 - [Upgrading from ejabberd 25.03 to 25.04](../../archive/25.04/upgrade.md)

content/archive/25.10/upgrade.md

@@ -0,0 +1,21 @@
+# Upgrade to ejabberd 25.10
+
+If you upgrade ejabberd from a previous release to [25.10](../../archive/25.10/index.md),
+there are no mandatory changes in SQL schemas, configuration, API commands or hooks.
+
+But if you are using the new SQL schema, it's recommended to update your setup
+to use the new arguments and option:
+
+When preparing configuration, replace the previous argument with the current argument:
+
+```
+./configure --enable-new-sql-schema
+./configure --enable-multihost-sql-schema
+```
+
+When configuring ejabberd, replace the previous option with the current option:
+
+```
+new_sql_schema: true
+sql_schema_multihost: true
+```