[DOCS] Adds release notes for 9.0.5 and 9.1.2

Author: picandocodigo

docs/release-notes/index.md

@@ -20,6 +20,12 @@ To check for security updates, go to [Security announcements for the Elastic sta
 % ### Fixes [elasticsearch-ruby-client-next-fixes]
 % *
 
+## 9.1.2 [elasticsearch-ruby-client-9.1.2-release-notes]
+
+- Fixes [2758](https://github.com/elastic/elasticsearch-ruby/issues/2758) - `msearch`, `bulk` and other NDJSON endpoints overriding headers for `content-type` and `accept`. [Pull Request](https://github.com/elastic/elasticsearch-ruby/pull/2759).
+- Adds `transform.set_upgrade_mode`.
+- Updates source code documentation from latest 9.1 Elasticsearch specification.
+
 ## 9.1.1 [elasticsearch-ruby-client-9.1.1-release-notes]
 
 ### Features and enhancements [elasticsearch-ruby-client-9.1.1-features-enhancements]
@@ -62,6 +68,11 @@ Tested versions of Ruby for 9.1.0: Ruby (MRI) 3.2, 3.3, 3.4, `head`, JRuby 9.3,
 - `streams.logs_enable` - Enable the Logs Streams feature for this cluster.
 - `streams.status` - Return the current status of the streams feature for each streams type.
 
+## 9.0.5 [elasticsearch-ruby-client-9.0.5-release-notes]
+
+- Fixes [2758](https://github.com/elastic/elasticsearch-ruby/issues/2758) - `msearch`, `bulk` and other NDJSON endpoints overriding headers for `content-type` and `accept`. [Pull Request](https://github.com/elastic/elasticsearch-ruby/pull/2759).
+- Adds `transform.set_upgrade_mode`.
+
 ## 9.0.4 [elasticsearch-ruby-client-9.0.4-release-notes]
 
 - Source code documentation and code has been updated to support common parameters and common cat parameters in APIs that support it (`error_trace`, `filter_path`, `human`, `pretty`). The API reference documentation can be generated with `rake doc`.