[DOCS]: Add connectors release notes for 9.1.6 (elastic#137123) (elastic#137272)

Co-authored-by: Matt Nowzari <[email protected]>

Author: charlotte-hoblik

docs/reference/search-connectors/release-notes.md

@@ -13,6 +13,13 @@ If you are an Enterprise Search user and want to upgrade to Elastic 9.0, refer t
 It includes detailed steps, tooling, and resources to help you transition to supported alternatives in 9.x, such as Elasticsearch, the Open Web Crawler, and self-managed connectors.
 :::
 
+## 9.1.6 [connectors-9.1.6-release-notes]
+
+### Features and enhancements [connectors-9.1.6-features-enhancements]
+* Idle Github connectors no longer excessively query set-up repositories, which reduces the number of calls to GitHub each connector makes and makes users less likely to hit GitHub API quotas. [#3708](https://github.com/elastic/connectors/pull/3708)
+
+* In the Sharepoint Online connector, /contentstorage/ URLs are no longer synced. [#3630](https://github.com/elastic/connectors/pull/3630)
+
 ## 9.1.5 [connectors-9.1.5-release-notes]
 
 ### Features and enhancements [connectors-9.1.5-features-enhancements]