[doc] Align agents logs documentation (#1837)

* change logs structure

* update content

* add ecs logging link

* fix link to config option for reformatting

* make doc fit the implementation

---------

Co-authored-by: Colton Myers <colton@basepi.net>

Author: SylvainJuge

docs/logging.asciidoc

@@ -1,34 +1,36 @@
-[[log-correlation]]
-== Log correlation
+[[logs]]
+== Logs
 
-Log correlation allows you to navigate to all logs belonging to a particular trace, and vice-versa -- for a specific log, see in which context it has been logged, and which parameters the user provided.
+Elastic Python APM Agent provides the following log features:
 
-The Agent provides integrations with both the default Python logging library,
-as well as http://www.structlog.org/en/stable/[`structlog`].
+- <<log-correlation-ids>> : Automatically inject correlation IDs that allow navigation between logs, traces and services.
+- <<log-reformatting>> : Automatically reformat plaintext logs in {ecs-logging-ref}/intro.html[ECS logging] format.
 
-* <<logging-integrations>>
-* <<log-correlation-in-es>>
+Those features are part of {observability-guide}/application-logs.html[Application log ingestion strategies].
+
+The {ecs-logging-python-ref}/intro.html[`ecs-logging-python`] library can also be used to use the {ecs-logging-ref}/intro.html[ECS logging] format without an APM agent.
+When deployed with the Python APM agent, the agent will provide <<log-correlation-ids,log correlation>> IDs.
 
 [float]
-[[ecs-logging]]
-=== `ecs-logging`
+[[log-correlation-ids]]
+=== Log correlation
 
-The easiest way to integrate your logs with APM is to use the
-https://github.com/elastic/ecs-logging-python[`ecs-logging`] library, which
-is also provided by Elastic. This library provides formatters for both `logging`
-and `structlog` which create ECS-compatible logs and will include the tracing
-information required for log correlation in kibana. Coupled with something like
-https://www.elastic.co/beats/filebeat[Filebeat], it is the easiest way to get
-logs into Elasticsearch.
+{apm-guide-ref}/log-correlation.html[Log correlation] allows you to navigate to all logs belonging to a particular trace
+and vice-versa: for a specific log, see in which context it has been logged and which parameters the user provided.
 
+The Agent provides integrations with both the default Python logging library,
+as well as http://www.structlog.org/en/stable/[`structlog`].
+
+* <<logging-integrations>>
+* <<log-correlation-in-es>>
 
 [float]
 [[logging-integrations]]
-=== Logging integrations
+==== Logging integrations
 
 [float]
 [[logging]]
-==== `logging`
+===== `logging`
 
 For Python 3.2+, we use https://docs.python.org/3/library/logging.html#logging.setLogRecordFactory[`logging.setLogRecordFactory()`]
 to decorate the default LogRecordFactory to automatically add new attributes to
@@ -66,7 +68,7 @@ your log handlers, as handlers are propagated, along with their attached filters
 
 [float]
 [[structlog]]
-==== `structlog`
+===== `structlog`
 
 We provide a http://www.structlog.org/en/stable/processors.html[processor] for
 http://www.structlog.org/en/stable/[`structlog`] which will add three new keys
@@ -174,3 +176,13 @@ Then, you could use a grok pattern like this (for the
   ]
 }
 ----
+
+[float]
+[[log-reformatting]]
+=== Log reformatting (experimental)
+
+The agent can automatically reformat application to ECS format when the application includes the `ecs-logging-python` library in its dependencies.
+
+Log reformatting is controlled by the <<config-log_ecs_reformatting, `log_ecs_reformatting`>> configuration option, and is disabled by default.
+
+The reformatted logs will include both the <<log-correlation-ids, trace and service correlation>> IDs.

docs/redirects.asciidoc

@@ -7,3 +7,8 @@ The following pages have moved or been deleted.
 === OpenTracing API
 
 Refer to <<opentelemetry-bridge>> instead.
+
+[role="exclude",id="log-correlation"]
+=== Log correlation
+
+Refer to <<logs>> instead.