Modify doc in app_insights metricset (#20185) (#20362)

(cherry picked from commit 3b4cdc2)

Co-authored-by: Mariana Dima <mariana@elastic.co>

CHANGELOG.next.asciidoc

@@ -346,6 +346,7 @@ field. You can revert this change by configuring tags for the module and omittin
 - Add missing info about the rest of the azure metricsets in the documentation. {pull}19601[19601]
 - Fix k8s scheduler compatibility issue. {pull}19699[19699]
 - Fix SQL module mapping NULL values as string {pull}18955[18955] {issue}18898[18898
+- Modify doc for app_insights metricset to contain example of config. {pull}20185[20185]
 
 *Packetbeat*
 

x-pack/metricbeat/module/azure/app_insights/_meta/docs.asciidoc

@@ -45,17 +45,15 @@ This value is only valid when segment is specified.
 `filter`:: (_string_) An expression used to filter the results.
 This value should be a valid OData filter expression where the keys of each clause should be applicable dimensions for the metric you are retrieving.
 
-Users can select the options to retrieve all metrics from a specific namespace using the following:
+Example configuration:
 
 ["source","yaml"]
 ----
- metrics:
- - id: ["*"]
-   timespan: "Microsoft.Storage/storageAccounts"
+metrics:
+ - id: ["requests/count", "requests/failed"]
+   segment: "request/name"
+   aggregation: ["sum"]
 ----
 
 
 
-A default non configurable timegrain of 5 min is set so users are advised to configure an interval of 300s or  a multiply of it.
-
-