Document comprehensive audit log event types (#8162)

* Document comprehensive audit log event types

- Add detailed "Audit event types" section with categorized list of all audit event names
- Include new example audit logs for createPost and patchConfig events
- Update JSON data model description to reference comprehensive event types list
- Address user feedback about insufficient audit log event documentation

Fixes #8161

Co-authored-by: Carrie Warner (Mattermost) <cwarnermm@users.noreply.github.com>

* Update source/comply/embedded-json-audit-log-schema.rst

* Document comprehensive audit log event types

- Replace limited audit event list with comprehensive list of all Mattermost audit events
- Organize events by functional category (User Management, Channel Management, etc.)
- Include detailed descriptions for each event type
- Remove event counts as requested
- Maintain proper RST table formatting for documentation consistency

Co-authored-by: Carrie Warner (Mattermost) <cwarnermm@users.noreply.github.com>

* Editorial review

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Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
Co-authored-by: Carrie Warner (Mattermost) <cwarnermm@users.noreply.github.com>

Author: cwarnermm