Archiver test doc update

[syntrust]

Fix comments during the demo. Major changes include:

• Reorg the table of contents
• Move the es-node setup to a later point to compare results with and without the archive service.
• Correct the incorrect command
• Update the beacon-api-wrapper to use epoch as the unit of retention time (per EIP-4844, which defines the retention period as 4096 epochs).
• Address inconsistencies in titles, etc.

Changes verified in the test environment.