8.8 Vulnerability Management documentation

[benironside]

In 8.8, we are introducing a new integration which scans AWS EC2 workloads for vulnerabilities: Elastic Vulnerability Management for Cloud (Cloud Native Vulnerability Management). This is being considered a security posture capability.

We need to add a section within the Cloud Native Security docs for vuln management, with at least two pages to start: an overview page, and a getting started page with deployment instructions.