customize_elasticsearch_index_structure.md: Update Elasticsearch link

Author: adriendupuis

docs/search/extensibility/customize_elasticsearch_index_structure.md

@@ -6,7 +6,7 @@ description: You can adapt the structure of Elasticsearch index to the data in y
 
 You can customize the structure of your Elasticsearch search index to manage how documents in the index are grouped.
 
-This lets you control the size of [Elasticsearch shards](https://www.elastic.co/guide/en/elasticsearch/reference/current/scalability.html) that the index is divided into.
+This lets you control the size of [Elasticsearch shards](https://www.elastic.co/docs/deploy-manage/production-guidance/scaling-considerations) that the index is divided into.
 
 By customizing the structure to your needs, you can avoid "oversharding" (having too many shards), which negatively affects performance and can lead to instability.