Miscellaneous fixes to ILM docs (#2564)

This addresses some of Edu's feedback on the ILM docs:

- In [Manually apply a lifecycle policy to an
index](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/2564/manage-data/lifecycle/index-lifecycle-management/policy-apply)
this adds use cases for doing the procedure, and also tries to improve
the contrast between manually applying an ILM policy versus applying it
using templates.
- In [View the lifecycle status of an index or data
stream](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/2564/manage-data/lifecycle/index-lifecycle-management/policy-view-status)
this adds links to the ILM troubleshooting docs.

Rel: [#190](elastic/docs-content-internal#190)

---------

Co-authored-by: Vlada Chirmicci <[email protected]>

Author: kilfoyle

manage-data/lifecycle/index-lifecycle-management/policy-apply.md

@@ -8,9 +8,14 @@ products:
 
 # Manually apply a lifecycle policy to an index [apply-policy-manually]
 
-When you create new {{es}} index you can use an index template to apply the lifecycle policy by which the index will be managed. This process is described in [Configure a lifecycle policy](/manage-data/lifecycle/index-lifecycle-management/configure-lifecycle-policy.md).
+When you create a new {{es}} index, it automatically picks up settings, mappings, and aliases from any matching [index template](/manage-data/data-store/templates.md#index-templates) and its component templates. If the template specifies a lifecycle policy, that policy is applied to the new index as soon as it's created. This process is described in detail in [Configure a lifecycle policy](/manage-data/lifecycle/index-lifecycle-management/configure-lifecycle-policy.md).
 
-You can also manually apply a lifecycle policy to an existing index, as described on this page. If an index is currently managed by an ILM policy you must first remove that policy before applying a new one. Refer to [Switch to a different lifecycle policy](/manage-data/lifecycle/index-lifecycle-management/policy-updates.md#switch-lifecycle-policies) for details.
+You can also apply a lifecycle policy manually to existing indices, as described on this page. This is useful if you want to:
+ * Configure the indices to move through different [data tiers](/manage-data/lifecycle/data-tiers.md) as they age.
+ * Perform [lifecycle actions](elasticsearch://reference/elasticsearch/index-lifecycle-actions/index.md) such as downsampling or shrinking.
+ * Delete the indices when they reach a certain age.
+
+If an index is currently managed by an ILM policy you must first remove that policy before applying a new one. Refer to [Switch to a different lifecycle policy](/manage-data/lifecycle/index-lifecycle-management/policy-updates.md#switch-lifecycle-policies) for details.
 
 You can do this procedure in {{kib}} or using the {{es}} API.
 

manage-data/lifecycle/index-lifecycle-management/policy-view-status.md

@@ -10,7 +10,13 @@ products:
 
 # View the lifecycle status of an index or data stream [view-lifecycle-status]
 
-For any existing managed index or data stream in your cluster, you can access the ILM policy applied to it and its current status.
+For any existing managed index or data stream in your cluster, you can access the {{ilm-init}} policy applied to it and its current status.
+
+You can view the lifecycle status of an index or data stream in {{kib}} or using the {{es}} API.
+
+:::{tip}
+If you're investigating an {{ilm-init}}-related problem, refer to [Troubleshoot index and snapshot lifecycle management](/troubleshoot/elasticsearch/start-ilm.md) and [Fix index lifecycle management errors](/troubleshoot/elasticsearch/index-lifecycle-management-errors.md) in the {{es}} chapter of the **Troubleshoot** section.
+:::
 
 :::::{tab-set}
 :group: kibana-api