Update Elastic Search documentation link

The heap size documentation reference on Elastic Search has moved to a
newer page/URL. This change updates the links and also adds another link
about configuring the actual JVM options.

doc/integration/elasticsearch.md

@@ -555,7 +555,7 @@ For basic guidance on choosing a cluster configuration you may refer to [Elastic
 - Generally, you will want to use at least a 2-node cluster configuration with one replica, which will allow you to have resilience. If your storage usage is growing quickly, you may want to plan horizontal scaling (adding more nodes) beforehand.
 - It's not recommended to use HDD storage with the search cluster, because it will take a hit on performance. It's better to use SSD storage (NVMe or SATA SSD drives for example).
 - You can use the [GitLab Performance Tool](https://gitlab.com/gitlab-org/quality/performance) to benchmark search performance with different search cluster sizes and configurations.
-- `Heap size` should be set to no more than 50% of your physical RAM. Additionally, it shouldn't be set to more than the threshold for zero-based compressed oops. The exact threshold varies, but 26 GB is safe on most systems, but can also be as large as 30 GB on some systems. See [Setting the heap size](https://www.elastic.co/guide/en/elasticsearch/reference/current/heap-size.html#heap-size) for more details.
+- `Heap size` should be set to no more than 50% of your physical RAM. Additionally, it shouldn't be set to more than the threshold for zero-based compressed oops. The exact threshold varies, but 26 GB is safe on most systems, but can also be as large as 30 GB on some systems. See [Heap size settings](https://www.elastic.co/guide/en/elasticsearch/reference/current/important-settings.html#heap-size-settings) and [Setting JVM options](https://www.elastic.co/guide/en/elasticsearch/reference/current/jvm-options.html) for more details.
 - Number of CPUs (CPU cores) per node usually corresponds to the `Number of Elasticsearch shards` setting described below.
 - A good guideline is to ensure you keep the number of shards per node below 20 per GB heap it has configured. A node with a 30GB heap should therefore have a maximum of 600 shards, but the further below this limit you can keep it the better. This will generally help the cluster stay in good health.
 - Small shards result in small segments, which increases overhead. Aim to keep the average shard size between at least a few GB and a few tens of GB. Another consideration is the number of documents, you should aim for this simple formula for the number of shards: `number of expected documents / 5M +1`.