[DOCS] Create Search landing page skeleton and stubs (#194293)

- Create Search landing page with links to all features available in the
Elastic Cloud hosted UI
- Create skeleton of a table to quickly provide links to all relevant
docs and release notes for each feature
- Currently commented out, to be filled in a follow-up PR by @kosabogi
- Create a stub page for connection details page (Docs equivalent to
[find your CloudID and create API
keys](https://www.elastic.co/search-labs/tutorials/install-elasticsearch/elastic-cloud#finding-your-cloud-id))
  - @kosabogi will update this page in follow-up
- Nest existing Playground docs under there
- Create a stub page for AI Assistant for Search docs
- Create a stub page for inference endpoints UI

docs/search/index.asciidoc

@@ -0,0 +1,73 @@
+[role="xpack"]
+[[search-space]]
+= Search
+
+The *Search* space in {kib} comprises the following features:
+
+* https://www.elastic.co/guide/en/enterprise-search/current/connectors.html[Connectors]
+* https://www.elastic.co/guide/en/enterprise-search/current/crawler.html[Web crawler]
+* <<playground,Playground>>
+* https://www.elastic.co/guide/en/elasticsearch/reference/current/search-application-overview.html[Search Applications]
+* https://www.elastic.co/guide/en/elasticsearch/reference/current/behavioral-analytics-overview.html[Behavioral Analytics]
+* Inference Endpoints UI
+* AI Assistant for Search
+* Persistent Dev Tools <<console-kibana, Console>>
+
+[float]
+[[search-release-notes]]
+== Docs and release notes
+
+The Search solution and use case is made up of many tools and features across the {stack}.
+As a result, the release notes for your features of interest might live in different Elastic docs.
+// Use the following table to find links to the appropriate documentation, API references (if applicable), and release notes.
+
+// [options="header"]
+// |===
+// | Name               | API reference           | Documentation         | Release notes
+
+// | Connectors
+// | link:https://example.com/connectors/api[API reference]
+// | link:https://example.com/connectors/docs[Documentation]
+// | link:https://example.com/connectors/notes[Release notes]
+
+// | Web crawler
+// | link:https://example.com/web_crawlers/api[API reference]
+// | link:https://example.com/web_crawlers/docs[Documentation]
+// | link:https://example.com/web_crawlers/notes[Release notes]
+
+// | Playground
+// | link:https://example.com/playground/api[API reference]
+// | link:https://example.com/playground/docs[Documentation]
+// | link:https://example.com/playground/notes[Release notes]
+
+// | Search Applications
+// | link:https://example.com/search_apps/api[API reference]
+// | link:https://example.com/search_apps/docs[Documentation]
+// | link:https://example.com/search_apps/notes[Release notes]
+
+// | Behavioral Analytics
+// | link:https://example.com/behavioral_analytics/api[API reference]
+// | link:https://example.com/behavioral_analytics/docs[Documentation]
+// | link:https://example.com/behavioral_analytics/notes[Release notes]
+
+// | Inference Endpoints
+// | link:https://example.com/inference_endpoints/api[API reference]
+// | link:https://example.com/inference_endpoints/docs[Documentation]
+// | link:https://example.com/inference_endpoints/notes[Release notes]
+
+// | Console
+// | link:https://example.com/console/api[API reference]
+// | link:https://example.com/console/docs[Documentation]
+// | link:https://example.com/console/notes[Release notes]
+
+// | Search UI
+// | link:https://www.elastic.co/docs/current/search-ui/api/architecture[API reference]
+// | link:https://www.elastic.co/docs/current/search-ui/overview[Documentation]
+// | link:https://example.com/search_ui/notes[Release notes]
+
+// |===
+
+include::search-connection-details.asciidoc[]
+include::playground/index.asciidoc[]
+include::search-ai-assistant/index.asciidoc[]
+include::inference-endpoints/index.asciidoc[]

docs/search/inference-endpoints/index.asciidoc

@@ -0,0 +1,5 @@
+[role="xpack"]
+[[inference-endpoints]]
+== Inference endpoints UI
+
+(coming in 8.16.0)

docs/search/playground/index.asciidoc

@@ -1,6 +1,6 @@
 [role="xpack"]
 [[playground]]
-= Playground
+== Playground
 
 preview::[]
 
@@ -22,7 +22,7 @@ Refer to the following for more advanced topics:
 
 [float]
 [[playground-how-it-works]]
-== How {x} works
+=== How {x} works
 
 Here's a simpified overview of how {x} works:
 
@@ -43,7 +43,7 @@ Here's a simpified overview of how {x} works:
 
 [float]
 [[playground-availability-prerequisites]]
-== Availability and prerequisites
+=== Availability and prerequisites
 
 For Elastic Cloud and self-managed deployments {x} is available in the *Search* space in {kib}, under *Content* > *{x}*.
 
@@ -102,14 +102,14 @@ Refer to the following for examples:
 
 [float]
 [[playground-getting-started]]
-== Getting started
+=== Getting started
 
 [.screenshot]
 image::get-started.png[width=600]
 
 [float]
 [[playground-getting-started-connect]]
-=== Connect to LLM provider
+==== Connect to LLM provider
 
 To get started with {x}, you need to create a <<action-types,connector>> for your LLM provider.
 You can also connect to <<playground-local-llms,locally hosted LLMs>> which are compatible with the OpenAI API, by using the OpenAI connector.
@@ -129,7 +129,7 @@ If you need to update a connector, or add a new one, click the 🔧 *Manage* but
 
 [float]
 [[playground-getting-started-ingest]]
-=== Ingest data (optional)
+==== Ingest data (optional)
 
 _You can skip this step if you already have data in one or more {es} indices._
 
@@ -168,7 +168,7 @@ These notebooks use the official {es} Python client.
 
 [float]
 [[playground-getting-started-index]]
-=== Select {es} indices
+==== Select {es} indices
 
 Once you've connected to your LLM provider, it's time to choose the data you want to search.
 
@@ -186,7 +186,7 @@ image::images/data-button.png[width=100]
 
 [float]
 [[playground-getting-started-chat-query-modes]]
-=== Chat and query modes
+==== Chat and query modes
 
 Since 8.15.0 (and earlier for {es} Serverless), the main {x} UI has two modes:
 
@@ -210,7 +210,7 @@ Learn more about the underlying {es} queries used to search your data in <<playg
 
 [float]
 [[playground-getting-started-setup-chat]]
-=== Set up the chat interface
+==== Set up the chat interface
 
 You can start chatting with your data immediately, but you might want to tweak some defaults first.
 
@@ -235,7 +235,7 @@ Click *⟳ Clear chat* to clear chat history and start a new conversation.
 
 [float]
 [[playground-getting-started-view-code]]
-=== View and download Python code
+==== View and download Python code
 
 Use the *View code* button to see the Python code that powers the chat interface.
 You can integrate it into your own application, modifying as needed.
@@ -249,7 +249,7 @@ image::images/view-code-button.png[width=100]
 
 [float]
 [[playground-next-steps]]
-=== Next steps
+==== Next steps
 
 Once you've got {x} up and running, and you've tested out the chat interface, you might want to explore some more advanced topics:
 

docs/search/playground/playground-context.asciidoc

@@ -1,6 +1,6 @@
 [role="xpack"]
 [[playground-context]]
-== Optimize model context
+=== Optimize model context
 
 preview::[]
 
@@ -22,7 +22,7 @@ Currently you can only select *one field* to be provided as context to the LLM.
 
 [float]
 [[playground-context-ui]]
-== Edit context in UI
+=== Edit context in UI
 
 Use the *Edit context* button in the {x} UI to adjust the number of documents and fields sent to the LLM.
 
@@ -33,13 +33,13 @@ If you're hitting context length limits, try the following:
 
 [float]
 [[playground-context-index]]
-== Other context optimizations
+=== Other context optimizations
 
 This section covers additional context optimizations that you won't be able to make directly in the UI.
 
 [float]
 [[playground-context-index-chunking]]
-=== Chunking large documents
+==== Chunking large documents
 
 If you're working with large fields, you may need to adjust your indexing strategy.
 Consider breaking your documents into smaller chunks, such as sentences or paragraphs.
@@ -56,7 +56,7 @@ Refer to the following Python notebooks for examples of how to chunk your docume
 
 [float]
 [[playground-context-balance]]
-=== Balancing cost/latency and result quality
+==== Balancing cost/latency and result quality
 
 Here are some general recommendations for balancing cost/latency and result quality with different context sizes:
 

docs/search/playground/playground-query.asciidoc

@@ -1,6 +1,6 @@
 [xpack]
 [[playground-query]]
-== View and modify queries
+=== View and modify queries
 
 :x:                    Playground
 
@@ -30,7 +30,7 @@ Learn more about <<playground-hidden-fields, hidden fields>>.
 
 [float]
 [[playground-query-relevance]]
-=== Improving relevance
+==== Improving relevance
 
 The fields you select in the query editor determine the relevance of the retrieved documents.
 
@@ -49,7 +49,7 @@ Refer to {ref}/retrievers-overview.html[documentation] for a high level overview
 
 [float]
 [[playground-hidden-fields]]
-=== Hidden fields
+==== Hidden fields
 
 The query editor shows fields which make sense for the user to search on, but not all fields in your documents are visible from the editor.
 

docs/search/playground/playground-troubleshooting.asciidoc

@@ -1,6 +1,6 @@
 [role="xpack"]
 [[playground-troubleshooting]]
-== Troubleshooting
+=== Troubleshooting
 
 preview::[]
 

docs/search/search-ai-assistant/index.asciidoc

@@ -0,0 +1,5 @@
+[role="xpack"]
+[[search-assistant]]
+== Search AI Assistant
+
+(coming in 8.16.0)

docs/search/search-connection-details.asciidoc

@@ -0,0 +1,7 @@
+[role="xpack"]
+[[search-space-connection-details]]
+== Find your connection details
+++++
+<titleabbrev>Connection details</titleabbrev>
+++++
+

docs/user/index.asciidoc

@@ -28,7 +28,7 @@ include::alerting/index.asciidoc[]
 
 include::{kibana-root}/docs/observability/index.asciidoc[]
 
-include::{kibana-root}/docs/playground/index.asciidoc[]
+include::{kibana-root}/docs/search/index.asciidoc[]
 
 include::{kibana-root}/docs/siem/index.asciidoc[]