Add Observability case templates

docs/en/observability/create-cases.asciidoc

@@ -7,6 +7,8 @@ add assignees and tags to your cases, set their severity and status, and add ale
 comments, and visualizations. You can also send cases to third party systems by
 <<cases-external-connectors,configuring external connectors>>.
 
+You can also optionally add custom fields and case templates. preview:[]
+
 [role="screenshot"]
 image::images/cases.png[Cases page]
 // NOTE: This is an autogenerated screenshot. Do not edit it directly.

docs/en/observability/manage-cases.asciidoc

@@ -1,21 +1,24 @@
 [[manage-cases]]
 = Open and manage new cases
 
+To perform these tasks, you must have <<grant-cases-access,full access>> to the {observability} case feature in {kib}.
+
 [discrete]
 [[new-case-observability]]
 == Open a new case
 
 Open a new case to keep track of issues and share the details with colleagues.
 
 . Go to *Cases* -> *Create new case*.
+. preview:[] If you defined <<observability-case-templates,templates>>, optionally select one to use its default field values.
 . Give the case a name, severity, and description.
 +
 TIP: In the `Description` area, you can use
 https://www.markdownguide.org/cheat-sheet[Markdown] syntax to create formatted text.
 
 . Optionally, add a category, assignees, and tags.
 You can add users only if they meet the necessary <<grant-cases-access,prerequisites>>.
-
+. preview:[] If you defined <<case-custom-fields,custom fields>>, they appear in the *Additional fields* section.
 . Under External incident management system, select a <<cases-external-connectors,connector>>. If
 you've previously added one, that connector displays as the default selection. Otherwise, the
 default setting is `No connector selected`.
@@ -35,8 +38,6 @@ You can add optional and required fields for customized case collaboration.
 [role="screenshot"]
 image::images/cases-custom-field-settings.png[View custom fields in case settings]
 // NOTE: This is an autogenerated screenshot. Do not edit it directly.
-
-NOTE: To view and change case settings, you must have the appropriate {kib} feature privileges. Refer to <<grant-cases-access>>.
 --
 
 . In the *Custom fields* section, click *Add field*.
@@ -142,3 +143,15 @@ To view a case, click on its name. You can then:
 * Refresh the case to retrieve the latest updates.
 * Close the case.
 * Reopen a closed case.
+
+[discrete]
+[[observability-case-templates]]
+== Case templates
+
+preview::[]
+
+You can make the case creation process faster and more consistent by adding templates in *Cases > Settings*.
+A template defines values for one or all of the case fields (such as severity, tags, description, and title) as well as any <<case-custom-fields,custom fields>>.
+When users create cases, they can optionally select a template and use its field values.
+
+NOTE: If you update or delete templates, existing cases are unaffected.