[docs] Add 7.6 breaking changes and release highlights (#16202) (#16218)

Author: dedemorton

libbeat/docs/release-notes/breaking/breaking-7.6.asciidoc

@@ -12,4 +12,18 @@
 
 //tag::notable-breaking-changes[]
 
+[float]
+==== Version removed from default ILM policy name
+
+To prevent custom ILM policies from breaking during upgrades, the default 
+ILM policy name no longer includes the {beats} version.
+
+If you want to include the version, use the `setup.ilm.policy_name`
+configuration setting. For example:
+
+[source,yaml]
+----
+setup.ilm.policy_name: "%{[agent.name]}-%{[agent.version]}"
+----
+
 // end::notable-breaking-changes[]

libbeat/docs/release-notes/highlights/highlights-7.6.0.asciidoc

@@ -7,8 +7,8 @@
 Each release of {beats} brings new features and product improvements. 
 Following are the most notable features and enhancements in 7.6.
 
-For a complete list of highlights, see the 
-https://www.elastic.co/blog/beats-7-6-0-released[{beats} 7.6 release blog].
+//For a complete list of highlights, see the 
+//https://www.elastic.co/blog/elastic-observability-7-6-0-released[Observability 7.6 release blog].
 
 For a list of bug fixes and other changes, see the {beats}
 <<breaking-changes-7.6, Breaking Changes>> and <<release-notes, Release Notes>>.
@@ -18,8 +18,67 @@ For a list of bug fixes and other changes, see the {beats}
 
 // tag::notable-highlights[]
 
-//[float]
-//==== Highlight
+[float]
+==== Support added for TLS 1.3
+
+In 7.6, we've added support for TLS 1.3, enabling you to take advantage
+of the security and performance improvements available in TLS 1.3 when {beats}
+connects to an {es} cluster that supports it.
+
+TLS 1.1, 1.2, and 1.3 are now enabled by default.
+
+[float]
+==== Azure cloud monitoring improvements
+
+The new {metricbeat-ref}/metricbeat-metricset-azure-storage.html[`storage`]
+metricset in the {metricbeat} {metricbeat-ref}/metricbeat-module-azure.html[Azure
+module] adds the ability to collect metrics from storage accounts.
+
+We've also made it easier for you to do a cost analysis on metrics
+collection by adding a cost warning message to each metrics API call. The
+message indicates the cost applied while retrieving metric values from Azure
+resources.
+
+[float]
+==== Google cloud monitoring improvements
+
+Starting with 7.6, you can deploy {functionbeat} as a Google Function via Google
+Cloud Deployment Manager and pull log events from
+https://cloud.google.com/pubsub/[Google Pub/Sub] and
+https://cloud.google.com/storage/[Google Cloud Storage]. 
+
+We've also expanded support in {metricbeat} by adding a beta release of the
+{metricbeat-ref}/metricbeat-module-googlecloud.html[Google Cloud Platform module].
+This module fetches monitoring metrics from Google Cloud Platform (GCP) by using
+the
+https://cloud.google.com/monitoring/api/metrics_gcp[Stackdriver Monitoring API]. 
+
+On the logging side, we've added two new filesets to the {filebeat}
+{filebeat-ref}/filebeat-module-googlecloud.html[Google Cloud module] to make it
+easier for you to ingest Gloogle Cloud logs:
+
+* The `audit` fileset parses
+https://cloud.google.com/logging/docs/audit/[Google Cloud Audit Logs].
+* The `firewall` fileset parses firewall logs generated by firewall rules
+logging.
+
+[float]
+==== Better support for document deduplication
+
+To help prevent duplicate events, we've introduced `document_id` settings
+in {beats} that you can use to set the document ID _before_ sending events to
+an output. The ID is stored in the {beats} `@metadata._id` field and used to
+set the document ID during indexing. Both the `decode_json_fields` processor and
+`json` options in the {filebeat} have been enhanced to include a
+`document_id` setting to use when decoding JSON data. 
+
+We've also added new processors for generating IDs when your data has no natural
+key field. The {filebeat-ref}/add-id.html[`add_id`] processor generates a unique
+ID for an event. The {filebeat-ref}/fingerprint.html[`fingerprint`] processor
+generates a fingerprint of an event based on a specified subset of its fields.
+
+To learn more, see {filebeat-ref}/filebeat-deduplication.html[Data
+deduplication].
 
 //Description