[DOCS] Add note to that log4j customization is outside the support scope (#82668)

* [docs] Add note to Elasticsearch logging that log4j customization is out of support scope

* Update language for default logging recommendation

Co-authored-by: Adam Locke <adam.locke@elastic.co>

Co-authored-by: Quin Hoxie <qhoxie@gmail.com>
Co-authored-by: Adam Locke <adam.locke@elastic.co>

docs/reference/setup/logging-config.asciidoc

@@ -14,6 +14,9 @@ If you run {es} from the command line, {es} prints logs to the standard output
 [[loggin-configuration]]
 === Logging configuration
 
+IMPORTANT: Elastic strongly recommends using the Log4j 2 configuration that is shipped by default.
+
+
 Elasticsearch uses https://logging.apache.org/log4j/2.x/[Log4j 2] for
 logging. Log4j 2 can be configured using the log4j2.properties
 file. Elasticsearch exposes three properties, `${sys:es.logs.base_path}`,