Project archival and deletion webhooks are inadequately documented

Issue Summary

The webhooks relating to project archival and deletion are inadequately documented. The webhooks are described in an announcement at https://community.developer.atlassian.com/t/stateful-project-in-jira-cloud-sign-up-for-feature-preview/36838, but not in the formal API documentation.

Steps to Reproduce

1. Attempt to find information about a webhooks relating to project archival and deletion events.

Expected Results

Information about the the following webhooks are found:

* project_archived

* project_restored_archived

* project_soft_deleted

* project_restored_deleted

Actual Results

Information about the webhook is NOT found. 

Workaround

None