add updateRun tsg and fix rollout doc

Author: jwtty

docs/concepts/StagedUpdateRun/README.md

@@ -119,3 +119,7 @@ This cluster-scoped resource requires three key parameters: the `placementName`
 An updateRun executes in two phases. During the initialization phase, the controller performs a one-time setup where it captures a snapshot of the updateRun strategy, collects scheduled and to-be-deleted `ClusterResourceBindings`, generates the cluster update sequence, and records all this information in the updateRun status.
 
 In the execution phase, the controller processes each stage sequentially, updates clusters within each stage one at a time, and enforces completion of after-stage tasks. It then executes a final delete stage to clean up resources from unscheduled clusters. The updateRun succeeds when all stages complete successfully. However, it will fail if any execution-affecting events occur, for example, the target ClusterResourcePlacement being deleted, and member cluster changes triggering new scheduling. In such cases, error details are recorded in the updateRun status. Remember that once initialized, an updateRun operates on its strategy snapshot, making it immune to subsequent strategy modifications.
+
+## Next Steps
+* Learn how to [rollout CRP resources with Staged Update Run](../../howtos/updaterun.md)
+* Learn how to [troubleshoot a Staged Update Run](../../troubleshooting/updaterun.md)

docs/troubleshooting/README.md

@@ -26,6 +26,7 @@ The complete progression of `ClusterResourcePlacement` is as follows:
     - If this condition is false, refer to [How can I debug when my CRP status is ClusterResourcePlacementScheduled condition status is set to false?](./clusterResourcePlacementScheduled.md). 
 2. `ClusterResourcePlacementRolloutStarted`: Indicates the rollout process has begun.
    - If this condition is false refer to [How can I debug when my CRP status is ClusterResourcePlacementRolloutStarted condition status is set to false?](./clusterResourcePlacementRolloutStarted.md)
+   - If you are triggering a rollout with a staged update run, refer to [Staged Update Run Troubleshooting Guide](./updaterun.md).
 3. `ClusterResourcePlacementOverridden`: Indicates the resource has been overridden.
    - If this condition is false, refer to [How can I debug when my CRP status is ClusterResourcePlacementOverridden condition status is set to false?](./clusterResourcePlacementOverridden.md)
 4. `ClusterResourcePlacementWorkSynchronized`: Indicates the work objects have been synchronized.

docs/troubleshooting/clusterResourcePlacementRolloutStarted.md

@@ -1,6 +1,10 @@
 # How can I debug when my CRP status is ClusterResourcePlacementRolloutStarted condition status is set to false?
 
 When using the `ClusterResourcePlacement` API object in Azure Kubernetes Fleet Manager to propagate resources, the selected resources aren't rolled out in all scheduled clusters and the `ClusterResourcePlacementRolloutStarted` condition status shows as `False`.
+
+*This TSG only applies to the `RollingUpdate` rollout strategy, which is the default strategy if you don't specify in the `ClusterResourcePlacement`.*
+*To troubleshoot the update run strategy as you specify `External` in the `ClusterResourcePlacement`, please refer to the [Staged Update Run Troubleshooting Guide](updaterun.md).*
+
 > Note: To get more information about why the rollout doesn't start, you can check the [rollout controller](https://github.com/Azure/fleet/blob/main/pkg/controllers/rollout/controller.go) to get more information on why the rollout did not start.
 
 ## Common scenarios: