Drafts REST API page in ES reference docs (elastic#129722)

* Drafts Elasticsearch landing page.

* Apply suggestions from code review

Co-authored-by: George Wallace <[email protected]>

* Changes links.

* Fixes relative links.

* Provide API descriptions.

* Adds API endpoint lists.

* Adds table.

* updating links

* fixing additional link

* fixing links

* Fixes more URLs.

* additional link fixes

* Fixes links CCR and above.

* Removes visual from landing page.

* Fixes URLs until the Inference section and above.

* Fixes URLs until Licensing and above.

* updated all links and landing page

* fixes

* updating urls

* Revert landing page changes except renaming.

---------

Co-authored-by: George Wallace <[email protected]>
Co-authored-by: George Wallace <[email protected]>

Author: szabosteve

docs/reference/elasticsearch/index.md

@@ -1,4 +1,4 @@
-# Elasticsearch and index management
+# Elasticsearch
 
 This section contains reference information for {{es}} and index management features.
 
@@ -7,7 +7,7 @@ To learn more about {{es}} features and how to get started, refer to the [{{es}}
 For more details about query and scripting languages, check these sections:
 * [Query languages](../query-languages/index.md)
 * [Scripting languages](../scripting-languages/index.md)
- 
+
 {{es}} also provides the following REST APIs:
 
 * [{{es}} API](https://www.elastic.co/docs/api/doc/elasticsearch)