Webhook Development Engagement with Secure stage

Description

As an exercise to aide in building a Webhook Development Guide, we've discussed a potential collaboration to support the Secure Stage in contributing a webhook for their Vulnerabilities feature. See: Additional Notification Options (&9470).

Goals

1. As Manage:Integrations is most familiar with the codebase for webhooks, we'd support and advise on the implementation, while the Secure team (Secure:Govern I believe in this case) would be familiar with their codebase for managing vulnerabilities and how they may be introduced (via API, streaming, or in the future "Continuous").
2. Manage:Integrations can use this exercise to build a first round of the Webhook Development Guide or use this for insight to improve it, depending on which effort comes first.