minor #19417 [Logger] Update ElasticsearchLogstashHandler documentation (alamirault)

This PR was merged into the 5.4 branch.

Discussion
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[Logger] Update ElasticsearchLogstashHandler documentation

Try fix #19412

1) Add link to Monolog source code for `FingersCrossedHandler` and `BufferHandler`
2) Add an example for production recommendation (Not tested but inspired by https://symfony.com/doc/current/logging.html#handlers-that-modify-log-entries example)

Commits
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07a9c8b Update ElasticsearchLogstashHandler documentation

Author: javiereguiluz

logging/handlers.rst

@@ -8,14 +8,6 @@ This handler deals directly with the HTTP interface of Elasticsearch. This means
 it will slow down your application if Elasticsearch takes time to answer. Even
 if all HTTP calls are done asynchronously.
 
-In a development environment, it's fine to keep the default configuration: for
-each log, an HTTP request will be made to push the log to Elasticsearch.
-
-In a production environment, it's highly recommended to wrap this handler in a
-handler with buffering capabilities (like the ``FingersCrossedHandler`` or
-``BufferHandler``) in order to call Elasticsearch only once with a bulk push. For
-even better performance and fault tolerance, a proper `ELK stack`_ is recommended.
-
 To use it, declare it as a service:
 
 .. configuration-block::
@@ -87,7 +79,10 @@ To use it, declare it as a service:
 
     The ``$elasticsearchVersion`` argument was introduced in Symfony 5.4.
 
-Then reference it in the Monolog configuration:
+Then reference it in the Monolog configuration.
+
+In a development environment, it's fine to keep the default configuration: for
+each log, an HTTP request will be made to push the log to Elasticsearch:
 
 .. configuration-block::
 
@@ -134,4 +129,69 @@ Then reference it in the Monolog configuration:
             ;
         };
 
+In a production environment, it's highly recommended to wrap this handler in a
+handler with buffering capabilities (like the `FingersCrossedHandler`_ or
+`BufferHandler`_) in order to call Elasticsearch only once with a bulk push. For
+even better performance and fault tolerance, a proper `ELK stack`_ is recommended.
+
+.. configuration-block::
+
+    .. code-block:: yaml
+
+        # config/packages/prod/monolog.yaml
+        monolog:
+            handlers:
+                main:
+                    type: fingers_crossed
+                    handler: es
+
+                es:
+                    type: service
+                    id: Symfony\Bridge\Monolog\Handler\ElasticsearchLogstashHandler
+
+    .. code-block:: xml
+
+        <!-- config/packages/prod/monolog.xml -->
+        <?xml version="1.0" encoding="UTF-8" ?>
+        <container xmlns="http://symfony.com/schema/dic/services"
+            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+            xmlns:monolog="http://symfony.com/schema/dic/monolog"
+            xsi:schemaLocation="http://symfony.com/schema/dic/services
+                https://symfony.com/schema/dic/services/services-1.0.xsd
+                http://symfony.com/schema/dic/monolog
+                https://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
+
+            <monolog:config>
+                <monolog:handler
+                    name="main"
+                    type="fingers_crossed"
+                    handler="es"
+                />
+                <monolog:handler
+                    name="es"
+                    type="service"
+                    id="Symfony\Bridge\Monolog\Handler\ElasticsearchLogstashHandler"
+                />
+            </monolog:config>
+        </container>
+
+    .. code-block:: php
+
+        // config/packages/prod/monolog.php
+        use Symfony\Bridge\Monolog\Handler\ElasticsearchLogstashHandler;
+        use Symfony\Config\MonologConfig;
+
+        return static function (MonologConfig $monolog): void {
+            $monolog->handler('main')
+                ->type('fingers_crossed')
+                ->handler('es')
+            ;
+            $monolog->handler('es')
+                ->type('service')
+                ->id(ElasticsearchLogstashHandler::class)
+            ;
+        };
+
+.. _`BufferHandler`: https://github.com/Seldaek/monolog/blob/main/src/Monolog/Handler/BufferHandler.php
 .. _`ELK stack`: https://www.elastic.co/what-is/elk-stack
+.. _`FingersCrossedHandler`: https://github.com/Seldaek/monolog/blob/main/src/Monolog/Handler/FingersCrossedHandler.php