Add connector release notes page

Author: charlotte-hoblik

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

@@ -0,0 +1,12 @@
+---
+navigation_title: "Release notes"
+---
+
+# Connector release notes
+
+:::{admonition} Enterprise Search is discontinued in Elastic 9.0.0
+Please note that Enterprise Search is not available in Elastic 9.0+, including App Search, Workplace Search, the Elastic Web Crawler, and Elastic managed connectors.
+
+If you are an Enterprise Search user and want to upgrade to Elastic 9.0, refer to [our Enterprise Search FAQ](https://www.elastic.co/resources/search/enterprise-search-faq#what-features-are-impacted-by-this-announcement).
+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.
+:::

docs/reference/search-connectors/toc.yml

@@ -63,4 +63,5 @@ toc:
 - file: use-cases.md
   children:
   - file: es-connectors-overview-architecture.md
-- file: es-connectors-known-issues.md
+- file: es-connectors-known-issues.md
+- file: release-notes.md