[Epic] EE: document audit log updates

[veod32]

PM ref.: https://www.notion.so/tarantool/Auditlog-for-Tarantool-EE-e4f9a4444cbf4ed195be6a0642345e68
Dev issue: https://github.com/tarantool/tarantool-ee/issues/54

SME: @ NeraverinTarantool , @ locker

Tasks

• https://github.com/tarantool/enterprise_doc/issues/139

Details

To document updates to the audit log functionality in Tarantool EE.