Document the outbox event processing APIs

Description

Document all the APIs exposed by the issues: HSEARCH-4132, HSEARCH-4134. HSEARCH-4140.

Environment

None

Assignee

Unassigned

Reporter

Fabio Massimo Ercoli

Labels

None

Suitable for new contributors

Yes, likely

Pull Request

None

Feedback Requested

None

Components

Fix versions

Priority

Major