[DOCS] Update 'Scalability and resilience' documentation with updated content

[kosabogi]

Description

The scalability section of the Elasticsearch guide needs to be updated with the content provided in this Google document.

[elasticsearchmachine]

Pinging @elastic/es-docs (Team:Docs)

[leemthompo]

@kosabogi because the basics page is now live, you're free to start working on porting @shainaraskas's draft to the scalability section. :)

[kosabogi]

Related PR: #113679