[DOCS] Moves X-Pack configuration pages in table of contents (#19182)

x-pack/docs/en/index.asciidoc

@@ -3,6 +3,8 @@
 
 include::{kib-repo-dir}/index-shared1.asciidoc[]
 
+include::setup/installing.asciidoc[]
+
 include::setup/setup-xkb.asciidoc[]
 
 include::{kib-repo-dir}/index-shared2.asciidoc[]

x-pack/docs/en/monitoring/monitoring-xkib.asciidoc

@@ -5,6 +5,10 @@
 <titleabbrev>Configuring Monitoring</titleabbrev>
 ++++
 
+{monitoring} gives you insight into the operation of your {stack}. For more 
+information, see <<xpack-monitoring,{monitoring}>> and 
+{stack-ov}/xpack-monitoring.html[Monitoring the {stack}]. 
+
 . To monitor {kib}:
 
 .. Verify that the `xpack.monitoring.collection.enabled` setting is `true` on

x-pack/docs/en/setup/setup-xkb.asciidoc

@@ -1,11 +1,10 @@
 [role="xpack"]
 [[setup-xpack-kb]]
-= Set Up {xpack}
+== Set Up {xpack}
 
-[partintro]
---
-{xpack} is an Elastic Stack extension that bundles security, alerting,
-monitoring, reporting, machine learning, and graph capabilities.
+{xpack} is an Elastic Stack extension that provides security, alerting,
+monitoring, reporting, machine learning, graph, and many other capabilities. By 
+default, when you install {kib}, {xpack} is installed.
 
 It adds the following pages to the side navigation:
 
@@ -14,18 +13,12 @@ It adds the following pages to the side navigation:
 * **Graph**
 * **Monitoring**
 
-
 The **Management** page gains options related to configuring security. The
 **Dev Tools** page gains a Search Profiler and a Grok Debugger. Where these and
 other {xpack} features are mentioned in this documentation, we've added an icon
 to clearly indicate that what you're reading pertains to features available only
 in {xpack}.
 
-For more information about how to obtain {xpack},
-see https://www.elastic.co/products/x-pack.
---
-
-include::installing.asciidoc[]
 include::{xkb-repo-dir}/monitoring/monitoring-xkib.asciidoc[]
 include::{xkb-repo-dir}/security/securing-kibana.asciidoc[]
 include::{xkb-repo-dir}/settings/settings-xkb.asciidoc[]