[HttpKernel] Document that Monolog handles the creation of log folder

Author: javiereguiluz

logging.rst

@@ -92,8 +92,14 @@ In the ``prod`` environment, logs are written to `STDERR PHP stream`_, which
 works best in modern containerized applications deployed to servers without
 disk write permissions.
 
-If you prefer to store production logs in a file, set the ``path`` of your
-log handler(s) to the path of the file to use (e.g. ``var/log/prod.log``).
+If you prefer to store production logs in a file, set the ``path`` option of your
+log handler(s) to the desired file path (e.g. ``var/log/prod.log``). This directory
+is created by Monolog if needed, so Symfony applications running on read-only
+filesystems don't need to create it manually or make it writable.
+
+.. versionadded:: 7.3
+
+    The feature to create the log directory automatically was introduced in Symfony 7.3.
 
 Handlers: Writing Logs to different Locations
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