doc: Clarify the 'review-docs-deploy' job documentation

What does this MR do?

This documents what's been done in !57727 (merged).

Review app:

• http://master-ee-58022.178.62.207.141.nip.io/ee/development/documentation/index.html#technical-aspects
• http://master-ee-58022.178.62.207.141.nip.io/ee/development/testing_guide/end_to_end/index.html#how-does-it-work