[DOCS] Reformat release highlights as What's new. (#58073)

docs/reference/index.asciidoc

@@ -12,6 +12,8 @@ include::../Versions.asciidoc[]
 
 include::intro.asciidoc[]
 
+include::release-notes/highlights.asciidoc[]
+
 include::getting-started.asciidoc[]
 
 include::setup.asciidoc[]
@@ -72,8 +74,6 @@ include::glossary.asciidoc[]
 
 include::rest-api/index.asciidoc[]
 
-include::release-notes/highlights.asciidoc[]
-
 include::migration/index.asciidoc[]
 
 include::release-notes.asciidoc[]

docs/reference/intro.asciidoc

@@ -1,7 +1,5 @@
 [[elasticsearch-intro]]
-= Elasticsearch introduction
-[partintro]
---
+== What is {es}?
 _**You know, for search (and analysis)**_
 
 {es} is the distributed search and analytics engine at the heart of
@@ -35,10 +33,9 @@ We’re continually amazed by the novel ways people use search. But whether
 your use case is similar to one of these, or you're using {es} to tackle a new
 problem, the way you work with your data, documents, and indices in {es} is
 the same.
---
 
 [[documents-indices]]
-== Data in: documents and indices
+=== Data in: documents and indices
 
 {es} is a distributed document store. Instead of storing information as rows of
 columnar data, {es} stores complex data structures that have been serialized
@@ -92,7 +89,7 @@ used at search time. When you query a full-text field, the query text undergoes
 the same analysis before the terms are looked up in the index.
 
 [[search-analyze]]
-== Information out: search and analyze
+=== Information out: search and analyze
 
 While you can use {es} as a document store and retrieve documents and their
 metadata, the real power comes from being able to easily access the full suite
@@ -108,7 +105,7 @@ or Ruby.
 
 [float]
 [[search-data]]
-=== Searching your data
+==== Searching your data
 
 The {es} REST APIs support structured queries, full text queries, and complex
 queries that combine the two. Structured queries are
@@ -133,7 +130,7 @@ third-party applications to interact with {es} via SQL.
 
 [float]
 [[analyze-data]]
-=== Analyzing your data
+==== Analyzing your data
 
 {es} aggregations enable you to build complex summaries of your data and gain
 insight into key metrics, patterns, and trends. Instead of just finding the
@@ -165,7 +162,7 @@ embroidery_ needles.
 
 [float]
 [[more-features]]
-==== But wait, there’s more
+===== But wait, there’s more
 
 Want to automate the analysis of your time-series data? You can use
 {ml-docs}/ml-overview.html[machine learning] features to create accurate
@@ -180,7 +177,7 @@ And the best part? You can do this without having to specify algorithms, models,
 or other data science-related configurations.
 
 [[scalability]]
-== Scalability and resilience: clusters, nodes, and shards
+=== Scalability and resilience: clusters, nodes, and shards
 ++++
 <titleabbrev>Scalability and resilience</titleabbrev>
 ++++
@@ -212,7 +209,7 @@ interrupting indexing or query operations.
 
 [float]
 [[it-depends]]
-=== It depends...
+==== It depends...
 
 There are a number of performance considerations and trade offs with respect
 to shard size and the number of primary shards configured for an index. The more
@@ -240,7 +237,7 @@ testing with your own data and queries].
 
 [float]
 [[disaster-ccr]]
-=== In case of disaster
+==== In case of disaster
 
 For performance reasons, the nodes within a cluster need to be on the same
 network. Balancing shards in a cluster across nodes in different data centers
@@ -260,7 +257,7 @@ secondary clusters are read-only followers.
 
 [float]
 [[admin]]
-=== Care and feeding
+==== Care and feeding
 
 As with any enterprise system, you need tools to secure, manage, and
 monitor your {es} clusters. Security, monitoring, and administrative features

docs/reference/release-notes/7.1.asciidoc

@@ -40,7 +40,7 @@ Also see <<breaking-changes-7.1,Breaking changes in 7.1>>.
 === Enhancements
 
 Security::
-* Moved some security features to basic. See <<release-highlights-7.1.0, 7.1.0 Release highlights>>
+* Moved some security features to basic. See {ref-bare/release-highlights-7.1.0.html[7.1.0 Release highlights].
 
 Authentication::
 * Log warning when unlicensed realms are skipped {pull}41778[#41778]

docs/reference/release-notes/highlights.asciidoc

@@ -1,29 +1,40 @@
 [[release-highlights]]
-= Release highlights
+== What's new in {minor-version}
 
-[partintro]
---
-This section summarizes the most important changes in each release. For the
-full list, see <<es-release-notes>> and <<breaking-changes>>.
+coming[{minor-version}]
 
-* <<release-highlights-7.8.0>>
-* <<release-highlights-7.7.0>>
-* <<release-highlights-7.6.0>>
-* <<release-highlights-7.5.0>>
-* <<release-highlights-7.4.0>>
-* <<release-highlights-7.3.0>>
-* <<release-highlights-7.2.0>>
-* <<release-highlights-7.1.0>>
-* <<release-highlights-7.0.0>>
+Here are the highlights of what's new and improved in {es} {minor-version}! 
+ifeval::["{release-state}"!="unreleased"]
+For detailed information about this release, see the 
+<<release-notes-{elasticsearch_version}, Release notes >>  and 
+<<breaking-changes-{minor-version}, Breaking changes>>.
+endif::[]
 
---
+// Add previous release to the list
+Other versions: 
+{ref-bare}/7.8/release-highlights.html[7.8] 
+| {ref-bare}/7.7/release-highlights.html[7.7]
+| {ref-bare}/7.7/release-highlights-7.6.0.html[7.6]
+| {ref-bare}/7.5/release-highlights-7.5.0.html[7.5]
+| {ref-bare}/7.4/release-highlights-7.4.0.html[7.4]
+| {ref-bare}/7.3/release-highlights-7.3.0.html[7.3]
+| {ref-bare}/7.2/release-highlights-7.2.0.html[7.2]
+| {ref-bare}/7.1/release-highlights-7.1.0.html[7.1]
+| {ref-bare}/7.0/release-highlights-7.0.0.html[7.0]
 
-include::highlights-7.8.0.asciidoc[]
-include::highlights-7.7.0.asciidoc[]
-include::highlights-7.6.0.asciidoc[]
-include::highlights-7.5.0.asciidoc[]
-include::highlights-7.4.0.asciidoc[]
-include::highlights-7.3.0.asciidoc[]
-include::highlights-7.2.0.asciidoc[]
-include::highlights-7.1.0.asciidoc[]
-include::highlights-7.0.0.asciidoc[]
+
+
+// Use the notable-highlights tag to mark entries that 
+// should be featured in the Stack Installation and Upgrade Guide:
+// tag::notable-highlights[] 
+// [discrete]
+// === Heading
+//
+// Description. 
+// end::notable-highlights[]
+
+// Omit the notable highlights tag for entries that only need to appear in the ES ref:
+// [float] 
+// === Heading
+//
+// Description.