docs: update documentation for shared ES after load tests

Description

Documentation and configuration change that results from load testing the ES cluster.

Supporting information

• https://tasks.opencraft.com/browse/SE-5873

Testing instructions

Steps to test the changes:

1. Run mkdocs serve
2. Proofread the docs and the code

Checklist

If any of the items below is not applicable, do not remove them, but put a check in it.

• All providers include the new feature/change
• All affected providers can provision new clusters
• Unit tests are added/updated
• Documentation is added/updated
• The TOOLS_CONTAINER_IMAGE_VERSION in ci_vars.yml is updated
• The grove-template repository is updated