Add Elastic Managed LLM known issue (#2112)

This PR closes [Issue
2088](#2088) and adds the
known issues page to the new docs, and adds a known issue regarding
Elastic Managed LLM being automatically selected as default collector.

---------

Co-authored-by: Viduni Wickramarachchi <viduni.ushanka@gmail.com>

Author: mdbirnstiehl

release-notes/elastic-observability/known-issues.md

@@ -0,0 +1,36 @@
+---
+navigation_title: Known issues
+---
+
+# {{observability}} known issues [elastic-observability-known-issues]
+Known issues are significant defects or limitations that may impact your implementation. These issues are actively being worked on and will be addressed in a future release. Review the {{observability}} known issues to help you make informed decisions, such as upgrading to a new version.
+
+% Use the following template to add entries to this page.
+
+% :::{dropdown} Title of known issue
+% Applies to: Applicable versions for the known issue
+% Description of the known issue.
+% For more information, check [Issue #](Issue link).
+% **Impact**<br> Impact of the known issue.
+% **Workaround**<br> Steps for a workaround until the known issue is fixed.
+
+% :::
+
+:::{dropdown} Observability AI Assistant - Elastic Managed LLM may be automatically selected as default connector
+
+Applies to: {{stack}} 9.x
+
+The Elastic Managed LLM may be automatically selected as your default connector because of existing connector selection logic.
+This can occur if you had not previously specified a connector for any of the following reasons:
+
+* You only had one connector available and it was always automatically picked for your conversations.
+* You had multiple connectors available but didn’t make a specific selection and used the automatically picked connector for your conversations.
+* You previously selected a connector but cleared your browser's local storage or switched browsers or devices.
+
+*And:*
+
+* All of your existing connector names come after the “Elastic Managed LLM connector" when sorted alphabetically.
+
+For more information, check [#2088](https://github.com/elastic/docs-content/issues/2088)
+
+::::

release-notes/elastic-observability/toc.yml

@@ -1,4 +1,5 @@
 toc:
   - file: index.md
+  - file: known-issues.md
   - file: breaking-changes.md
   - file: deprecations.md