[DOCS] 9.1.6 release notes (#240135)

Fixes elastic/docs-content#3586

Preview -
https://docs-v3-preview.elastic.dev/elastic/kibana/pull/240135/release-notes

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Co-authored-by: wajihaparvez <wajiha.parvez@elastic.co>

Author: nastasha-solomon

docs/release-notes/index.md

@@ -21,8 +21,48 @@ To check for security updates, go to [Security announcements for the Elastic sta
 % ### Fixes [kibana-X.X.X-fixes]
 % *
 
-% FEATURES, ENHANCEMENTS, FIXES
-% Paste in index.md
+
+## 9.1.6 [kibana-9.1.6-release-notes]
+
+% ::::{NOTE}
+% ::::
+
+
+### Features and enhancements [kibana-9.1.6-features-enhancements]
+
+**Data ingestion and Fleet**:
+* Replaces the `?showAgentless` query param with a local storage setting called `fleet:showAgentlessResources`, which can be toggled from the {{fleet}} settings page. When enabled, agentless agents and policies are visible in the {{fleet}} UI [#237528]({{kib-pull}}237528).
+
+**Elastic Security solution**:
+For the Elastic Security 9.1.6 release information, refer to [Elastic Security Solution Release Notes](docs-content://release-notes/elastic-security/index.md).
+
+**Kibana security**:
+* Enhances error message by explaining why the role is considered malformed [#239098]({{kib-pull}}239098).
+
+
+### Fixes [kibana-9.1.6-fixes]
+
+**Dashboards and Visualizations**:
+* Fixes bug that prevented you from deleting unsaved dashboard changes after you had enabled the `timeRestore` setting and selected a time and date using the date picker [#239992]({{kib-pull}}239992).
+* Fixes error that occured when you selected a blank value in the options list [#239791]({{kib-pull}}239791).
+* Fixes a bug in Lens that incorrectly assigned unsaved, ad-hoc dataview references [#239431]({{kib-pull}}239431).
+* Fixes metric color assignment when breakdown and a max dimension are defined in Lens [#238901]({{kib-pull}}238901).
+* Ensures adhoc dataviews from {{esql}} charts aren't being filtered out in the KQL search bar [#238731]({{kib-pull}}238731).
+
+**Data ingestion and Fleet**:
+* Fixes bug that occured during an integration policy upgrade that prevented the new package global variables from being included and stale variable references from being removed [#238542]({{kib-pull}}238542).
+
+**Discover**:
+* Ensures that the combined filters are considered when selecting the correct fields for the query while the `courier:ignoreFilterIfFieldNotInIndex` advanced setting is enabled [#238945]({{kib-pull}}238945).
+
+**Elastic Observability solution**:
+For the Elastic Observability 9.1.6 release information, refer to [Elastic Observability Solution Release Notes](docs-content://release-notes/elastic-observability/index.md).
+
+**Elastic Security solution**:
+For the Elastic Security 9.1.6 release information, refer to [Elastic Security Solution Release Notes](docs-content://release-notes/elastic-security/index.md).
+
+**Search**:
+* Fixes visual issues with the document metadata popup that happened when the document ID was too long. Also adds a tooltip and copy button to improve the user experience [#239768]({{kib-pull}}239768).
 
 ## 9.1.5 [kibana-9.1.5-release-notes]