docs: Add "deprecating soon" notices

docs/apm-components.asciidoc

@@ -1,12 +1,32 @@
 [[apm-components]]
-=== Components and documentation
+== Components and documentation
 
-Elastic APM consists of four components: *APM agents*, *Elastic Agent*, *Elasticsearch*, and *Kibana*.
+****
+There are two ways to install, run, and manage Elastic APM:
+
+* With the Elastic APM integration
+* With the standalone (legacy) APM Server binary
+
+This documentation focuses on option one: the **Elastic APM integration**.
+For standalone APM Server (legacy) documentation, please see the <<legacy-apm-overview>>
+and <<overview>>.
+****
+
+Elastic APM consists of four components: *APM agents*, the *Elastic APM integration*, *Elasticsearch*, and *Kibana*.
+Generally, there are two ways that these four components can work together:
+
+Apm agents on edge machines send data to a centrally hosted APM integration:
 
 image::./images/apm-architecture.png[Architecture of Elastic APM]
 
+Or, APM agents and the APM integration live on edge machines and enroll via a centrally hosted {agent}:
+
+image::./images/apm-architecture-two.png[Architecture of Elastic APM option two]
+
+Read on to learn more about each of these components!
+
 [float]
-==== APM Agents
+=== APM Agents
 
 APM agents are open source libraries written in the same language as your service.
 You may only need one, or you might use all of them.
@@ -27,26 +47,28 @@ Each agent has its own documentation:
 * {apm-rum-ref-v}/intro.html[JavaScript Real User Monitoring (RUM) agent]
 
 [float]
-==== Elastic Agent
+[[apm-integration]]
+=== Elastic APM integration
 
-Elastic Agent is a single, unified way to add monitoring for logs, metrics, traces, and other types of data to each host.
-A single agent makes it easier and faster to deploy monitoring across your infrastructure.
-The agent’s single, unified policy makes it easier to add integrations for new data sources.
-
-The APM integration within Elastic Agent receives performance data from your APM agents,
+The APM integration receives performance data from your APM agents,
 validates and processes it, and then transforms the data into {es} documents.
 Removing this logic from APM agents help keeps them light, prevents certain security risks,
 and improves compatibility across the Elastic Stack.
 
+The Elastic integration runs on {fleet-guide}[{agent}]. {agent} is a single, unified way to add monitoring for logs,
+metrics, traces, and other types of data to each host.
+A single agent makes it easier and faster to deploy monitoring across your infrastructure.
+The agent’s single, unified policy makes it easier to add integrations for new data sources.
+
 [float]
-==== Elasticsearch
+=== Elasticsearch
 
 {ref}/index.html[Elasticsearch] is a highly scalable free and open full-text search and analytics engine.
 It allows you to store, search, and analyze large volumes of data quickly and in near real time.
 Elasticsearch is used to store APM performance metrics and make use of its aggregations.
 
 [float]
-==== Kibana APM app
+=== Kibana APM app
 
 {kibana-ref}/index.html[Kibana] is a free and open analytics and visualization platform designed to work with Elasticsearch.
 You use Kibana to search, view, and interact with data stored in Elasticsearch.

docs/integrations-index.asciidoc

@@ -1,5 +1,6 @@
 include::./version.asciidoc[]
 include::{asciidoc-dir}/../../shared/attributes.asciidoc[]
+include::./notices.asciidoc[]
 
 :apm-integration-docs:
 :apm-package-dir:    {docdir}/apm-package
@@ -45,8 +46,8 @@ include::upgrade.asciidoc[]
 
 include::release-notes.asciidoc[leveloffset=+1]
 
-// This includes the legacy APM Overview
+// Legacy APM Overview
 include::legacy/guide/index.asciidoc[]
 
-// This includes the legacy APM Server Reference
+// Legacy APM Server Reference
 include::legacy/index.asciidoc[]

docs/legacy/agent-configuration.asciidoc

@@ -5,6 +5,9 @@
 <titleabbrev>Agent configuration</titleabbrev>
 ++++
 
+IMPORTANT: {deprecation-notice-api}
+If you've already upgraded, see <<api-config>>.
+
 APM Server exposes an API endpoint that allows agents to query the server for configuration changes.
 More information on this feature is available in {kibana-ref}/agent-configuration.html[APM Agent configuration in Kibana].
 

docs/legacy/api-keys.asciidoc

@@ -2,6 +2,9 @@
 [[beats-api-keys]]
 == Grant access using API keys
 
+IMPORTANT: {deprecation-notice-config}
+If you've already upgraded, see <<api-key>>.
+
 Instead of using usernames and passwords, you can use API keys to grant
 access to {es} resources. You can set API keys to expire at a certain time,
 and you can explicitly invalidate them. Any user with the `manage_api_key`

docs/legacy/common-problems.asciidoc

@@ -1,6 +1,8 @@
 [[common-problems]]
 == Common problems
 
+IMPORTANT: {deprecation-notice-data}
+
 This section describes common problems you might encounter with APM Server.
 
 * <<no-data-indexed>>

docs/legacy/config-ownership.asciidoc

@@ -1,3 +1,4 @@
+[float]
 [[config-file-ownership]]
 ==== Configuration file ownership
 
@@ -36,6 +37,7 @@ can only be writable by the owner but the permissions are "-rw-rw-r--"
 To correct this problem, use +chmod go-w /etc/{beatname_lc}/{beatname_lc}.yml+ to
 remove write privileges from anyone other than the owner.
 
+[float]
 ===== Disabling strict permission checks
 
 You can disable strict permission checks from the command line by using

docs/legacy/configuration-anonymous.asciidoc

@@ -5,6 +5,9 @@
 <titleabbrev>Anonymous authentication</titleabbrev>
 ++++
 
+IMPORTANT: {deprecation-notice-config}
+If you're using {fleet} and the Elastic APM integration, please see <<input-apm>> instead.
+
 Elastic APM agents can send unauthenticated (anonymous) events to the APM Server.
 This is useful for agents that run on clients, like the Real User Monitoring (RUM) agent running in a browser,
 or the iOS/Swift agent running in a user application.