[DOCS] Maintenance window column in alerts tables (elastic#158125)

(cherry picked from commit 1b71d2c)

docs/management/maintenance-windows/maintenance-windows.asciidoc

@@ -46,4 +46,6 @@ A maintenance window can have any one of the following statuses:
 - `Upcoming`: It will run at the scheduled date and time.
 - `Running`: It is running.
 - `Finished`: It ended and does not have a repeat schedule.
-- `Archived`: It is archived. In a future release, archived maintenance windows will be queued for deletion.
+- `Archived`: It is archived. In a future release, archived maintenance windows will be queued for deletion.
+
+When you <<rule-details,view alert details>> in {kib}, each alert shows unique identifiers for maintenance windows that affected it.

docs/user/alerting/create-and-manage-rules.asciidoc

@@ -1,6 +1,10 @@
 [role="xpack"]
 [[create-and-manage-rules]]
 == Create and manage rules
+:frontmatter-description: Set up alerting in the {kib} {stack-manage-app} app and manage your rules.
+:frontmatter-tags-products: [kibana, alerting]
+:frontmatter-tags-content-type: [how-to]
+:frontmatter-tags-user-goals: [manage]
 
 The *{stack-manage-app}* > *{rules-ui}* UI provides a cross-app view of alerting.
 Different {kib} apps like {observability-guide}/create-alerts.html[*{observability}*],
@@ -183,6 +187,9 @@ When an alert is created, it generates actions. If the conditions that caused th
 
 NOTE: The `flapping` state is possible only if you have enabled alert flapping detection in *{stack-manage-app}* > *{rules-ui}* > *Settings*. For each space, you can choose a look back window and threshold that are used to determine whether alerts are flapping. For example, you can specify that the alert must change status at least 6 times in the last 10 runs. If the rule has actions that run when the alert status changes, those actions are suppressed while the alert is flapping.
 
+If an alert was affected by a maintenance window, its identifier appears in the *Maintenance windows* column.
+For more information about their impact on alert notifications, refer to <<maintenance-windows>>.
+
 You can suppress future actions for a specific alert by turning on the *Mute* toggle. If a muted alert no longer meets the rule conditions, it stays in the list to avoid generating actions if the conditions recur. You can also disable a rule, which stops it from running checks and clears any alerts it was tracking. You may want to disable rules that are not currently needed to reduce the load on {kib} and {es}.
 
 [role="screenshot"]