Clarify that advanced search is not on GitLab.com

doc/user/search/advanced_global_search.md

-# Advanced Global Search **[STARTER]**
+# Advanced Global Search **[STARTER ONLY]**
 
 > - [Introduced][ee-109] in GitLab [Starter][ee] 8.4.
 > - This is the user documentation. To install and configure Elasticsearch,
 >   visit the [admin docs](../../integration/elasticsearch.md).
 
+NOTE: **Note**
+Advanced Global Search (powered by Elasticsearch) is not yet available on GitLab.com. We are working on adding it. [Follow for latest updates](https://gitlab.com/groups/gitlab-org/-/epics/153).
+
 Leverage Elasticsearch for faster, more advanced code search across your entire
 GitLab instance.
 

doc/user/search/advanced_search_syntax.md

-# Advanced Syntax Search **[STARTER]**
+# Advanced Syntax Search **[STARTER ONLY]**
 
 > **Notes:**
 > - Introduced in [GitLab Enterprise Starter][ee] 9.2
 > - This is the user documentation. To install and configure Elasticsearch,
 >   visit the [admin docs](../../integration/elasticsearch.md).
 
+NOTE: **Note**
+Advanced Global Search (powered by Elasticsearch) is not yet available on GitLab.com. We are working on adding it. [Follow for latest updates](https://gitlab.com/groups/gitlab-org/-/epics/153).
+
 Use advanced queries for more targeted search results.
 
 ## Overview