As an user of OpenShift managed Elasticsearch, I want to be able to delete logs for noisy tenants while still retaining other namespaces.

Acceptance Criteria:

• Provide documentation on how customers can perform a delete by query call to Elasticsearch to clean up logs from noisy namespaces.

Notes: 

• Elasticsearch outlines how to do this in their docs, we should provide a couple examples on how to do this in our repo docs and also our official docs
  • https://www.elastic.co/guide/en/elasticsearch/reference/6.8/docs-delete-by-query.html
• If possible, we should try to ensure our examples are written such that they ignore the current `-write` indices