[8.16] [Serverless bug bash] Updates cases API link (backport #6160) (#6213)

* [Serverless bug bash] Updates cases API link (#6160)

* Updates cases API link

* replaces link

(cherry picked from commit 115cbe6)

# Conflicts:
#	docs/serverless/alerts/signals-to-cases.asciidoc
#	docs/serverless/investigate/cases-open-manage.asciidoc
#	docs/serverless/investigate/cases-overview.asciidoc

* Delete docs/serverless directory and its contents

---------

Co-authored-by: natasha-moore-elastic <[email protected]>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: 3 people

docs/cases/cases-manage.asciidoc

@@ -5,7 +5,7 @@
 :frontmatter-tags-content-type: [how-to] 
 :frontmatter-tags-user-goals: [analyze]
 
-You can create and manage cases using the UI or the <<cases-api-overview>>.
+You can create and manage cases using the UI or the {api-kibana}/group/endpoint-cases[cases API].
 
 [float]
 [[cases-ui-open]]

docs/cases/cases-overview.asciidoc

@@ -5,7 +5,7 @@
 :frontmatter-tags-content-type: [overview] 
 :frontmatter-tags-user-goals: [analyze]
 
-Collect and share information about security issues by opening a case in {elastic-sec}. Cases allow you to track key investigation details, collect alerts in a central location, and more. The {elastic-sec} UI provides several ways to create and manage cases. Alternatively, you can use the <<cases-api-overview,cases API>> to perform the same tasks.
+Collect and share information about security issues by opening a case in {elastic-sec}. Cases allow you to track key investigation details, collect alerts in a central location, and more. The {elastic-sec} UI provides several ways to create and manage cases. Alternatively, you can use the {api-kibana}/group/endpoint-cases[cases API] to perform the same tasks.
 
 You can also send cases to these external systems by <<cases-ui-integrations, configuring external connectors>>:
 

docs/detections/alerts-add-to-cases.asciidoc

@@ -9,7 +9,7 @@ From the Alerts table, you can attach one or more alerts to a <<signals-to-new-c
 
 [NOTE]
 ===============================
-* After you add an alert to a case, you can remove it from the case activity under the alert summary or by using the <<cases-api-overview,Elastic Security Cases API>>.
+* After you add an alert to a case, you can remove it from the case activity under the alert summary or by using the {api-kibana}/group/endpoint-cases[cases API].
 * Each case can have a maximum of 1,000 alerts.
 ===============================