Add agent.monitoring.pprof doc (#1265) (#1277)

* Add agent.monitoring.pprof doc

Add some explanation for the agent.monitoring.pprof option, and when to
disable it, in the stand-alone documentation.

* Apply suggestions from code review

Co-authored-by: DeDe Morton <dede.morton@elastic.co>

Co-authored-by: DeDe Morton <dede.morton@elastic.co>

Co-authored-by: DeDe Morton <dede.morton@elastic.co>

docs/en/ingest-management/elastic-agent/configuration/elastic-agent-monitoring.asciidoc

@@ -21,6 +21,9 @@ agent.monitoring:
   logs: true
   # enables metrics monitoring
   metrics: true
+  # exposes /debug/pprof/ endpoints
+  # enable these endpoints if the monitoring endpoint is set to localhost
+  pprof: true
   # specifies output to be used
   use_output: monitoring
 ----
@@ -32,4 +35,9 @@ are ignored.
 To enable monitoring, set `agent.monitoring.enabled` to `true`. Also set the
 `logs` and `metrics` settings to control whether logs, metrics, or both are
 collected. If neither setting is specified, monitoring is turned off. Set
-`use_output` to specify the output to which monitoring events are sent.
+`use_output` to specify the output to which monitoring events are sent.
+
+The `agent.monitoring.pprof` option controls whether the {agent} exposes the
+`/debug/pprof/` endpoints with the monitoring endpoints. It is set to `true`
+by default. If the monitoring endpoint is accessible over a network (not recommended),
+set this option to `false` to disable the `/debug/pprof/` endpoints.