[DOCS] Adds Transform alerts docs (#78185)

docs/reference/transform/index.asciidoc

@@ -2,6 +2,7 @@ include::transforms.asciidoc[leveloffset=+1]
 include::overview.asciidoc[leveloffset=+2]
 include::setup.asciidoc[leveloffset=+2]
 include::usage.asciidoc[leveloffset=+2]
+include::transform-alerts.asciidoc[leveloffset=+2]
 include::transforms-at-scale.asciidoc[leveloffset=+2]
 include::checkpoints.asciidoc[leveloffset=+2]
 include::api-quickref.asciidoc[leveloffset=+2]

docs/reference/transform/transform-alerts.asciidoc

@@ -0,0 +1,87 @@
+[role="xpack"]
+[[transform-alerts]]
+= {transform-cap} alerts
+
+beta::[]
+
+{kib} {alert-features} include support for {transform} rules, which check the 
+health of {ctransforms} with certain conditions. If the conditions of the rule 
+are met, an alert is created and the associated action is triggered. For 
+example, you can create a rule to check if a {ctransform} is started and to 
+notify you in an email if it is not. To learn more about {kib} {alert-features}, 
+refer to 
+{kibana-ref}/alerting-getting-started.html#alerting-getting-started[Alerting].
+
+The following {transform} rules are available:
+
+{transform-cap} health:: 
+  Monitors {transforms} health and alerts if an operational issue occurred.
+
+
+[[creating-transform-rules]]
+== Creating a rule
+
+You can create {transform} rules under **{stack-manage-app} > {rules-ui}**.
+
+On the *Create rule* window, give a name to the rule and optionally provide 
+tags. Specify the time interval for the rule to check {transform} health 
+changes. You can also select a notification option with the _Notify_ selector. 
+An alert remains active as long as the configured conditions are met during the 
+check interval. When there is no matching condition in the next interval, the 
+`Recovered` action group is invoked and the status of the alert changes to `OK`. 
+For more details, refer to the documentation of 
+{kibana-ref}/create-and-manage-rules.html#defining-rules-general-details[general rule details].
+
+Select the {transform-cap} health rule type under the Stack Monitoring section.
+
+[role="screenshot"]
+image::images/transform-rule.png["Creating a transform health rule"]
+
+
+[[creating-transform-health-rules]]
+=== {transform-cap} health
+
+Select the {transform} or {transforms} to include. You can also use a special 
+character (`*`) to apply the rule to all your {transforms}. {transforms-cap} 
+created after the rule are automatically included.
+
+The following health check is available and enabled by default:
+
+_{transform-cap} is not started_:: 
+  Notifies if the corresponding {transforms} is not started or it does not index 
+  any data. The notification message recommends the necessary actions to solve 
+  the error.
+
+[role="screenshot"]
+image::images/transform-check-config.png["Selecting health check"]
+
+As the last step in the rule creation process, 
+<<defining-actions, define the actions>> that occur when the conditions
+are met.
+  
+
+[[defining-actions]]
+== Defining actions
+
+Connect your rule to actions that use supported built-in integrations by 
+selecting a connector type. Connectors are {kib} services or third-party 
+integrations that perform an action when the rule conditions are met.
+
+[role="screenshot"]
+image::images/transform-alert-actions.png["Selecting connector type"]
+
+
+For example, you can choose _Slack_ as a connector type and configure it to send 
+a message to a channel you selected. You can also create an index connector that 
+writes the JSON object you configure to a specific index. It's also possible to 
+customize the notification messages. A list of variables is available to include 
+in the message, like {transform} ID, description, {transform} state, and so on.
+
+After you save the configurations, the rule appears in the *{rules-ui}* list 
+where you can check its status and see the overview of its configuration 
+information.
+
+The name of an alert is always the same as the {transform} ID of the associated 
+{transform} that triggered it. You can mute the notifications for a particular 
+{transform} on the page of the rule that lists the individual alerts. You can 
+open it via *{rules-ui}* by selecting the rule name.

docs/reference/transform/transforms.asciidoc

@@ -14,6 +14,7 @@ documents that have a certain unique key.
 * <<transform-overview>>
 * <<transform-setup>>
 * <<transform-usage>>
+* <<transform-alerts>>
 * <<transform-scale>>
 * <<transform-checkpoints>>
 * <<transform-api-quickref>>