[DOCS] Updates release notes for 8.10

docs/release_notes/810.asciidoc

@@ -0,0 +1,51 @@
+[[release_notes_8100]]
+=== 8.10 Release notes
+
+[discrete]
+[[release_notes_810_0]]
+=== 8.10.0 Release notes
+
+[discrete]
+=== Client
+* Tested versions of Ruby for 8.10.0: Ruby (MRI) 3.0, 3.1 and 3.2. JRuby 9.3 and JRuby 9.4.
+
+[discrete]
+=== API
+
+[discrete]
+==== New Experimental APIs, for internal use:
+- `fleet.delete_secret`
+- `fleet.get_secret`
+- `fleet.post_secret`
+
+[discrete]
+==== New stable APIs:
+- `security.get_settings` - Retrieve settings for the security system indices
+- `security.update_settings` - Update settings for the security system indices
+
+[discrete]
+==== New Experimental API:
+- `query_ruleset.list` List query rulesets.
+
+[discrete]
+==== API Changes:
+- `indices.reload_search_analyzers` - Adds parameter `resource` changed resource to reload analyzers from if applicable
+
+Promoted from Experimental to Beta:
+
+- `security.create_cross_cluster_api_key`
+- `security.update_cross_cluster_api_key`
+
+[discrete]
+==== Synonyms namespace update:
+
+All synonym related APIs have been moved to the `synonyms` namespace and some of the endpoints have been renamed, as well as their parameters:
+
+- `synonyms.delete` => `synonyms.delete_synonym` - requires `id`, the id of the synonyms set to be deleted.
+- `synonyms.get` => `synonyms.get_synonym` - requires `id`, the name of the synonyms set to be retrieved.
+- `synonyms_set.get_synonyms_sets` => `synonyms.get_synonyms_sets`
+- `synonyms.put` => `synonyms.put_synonym` - requires `id` of the synonyms set to be created or updated.
+- `synonym_rule.put` => `synonyms.put_synonym_rule` - Parameters changed to `set_id` (the id of the synonym set to be updated with the synonym rule) and `rule_id` (the id of the synonym rule to be updated or created).
+- New Experimental API `synonyms.delete_synonym_rule` - Deletes a synonym rule in a synonym set
+- New Experimental API `synonyms.get_synonym_rule` - Retrieves a synonym rule from a synonym set
+

docs/release_notes/index.asciidoc

@@ -3,6 +3,7 @@
 
 [discrete]
 === 8.x
+* <<release_notes_8100, 8.10 Release Notes>>
 * <<release_notes_89, 8.9 Release Notes>>
 * <<release_notes_88, 8.8 Release Notes>>
 * <<release_notes_87, 8.7 Release Notes>>
@@ -31,6 +32,7 @@
 * <<release_notes_75, 7.5 Release Notes>>
 * <<release_notes_70, 7.0 Release Notes>>
 
+include::810.asciidoc[]
 include::89.asciidoc[]
 include::88.asciidoc[]
 include::87.asciidoc[]