feat: Add a security section to the guide #843

Agentic AI has drastically changed the security landscape by making vulnerabilities much easier to discover and exploit. This puts a lot of pressure on maintainers to stay vigilant and respond quickly to new threats by updating and patching their packages. It also makes good security hygiene more important than ever.

We could add a section to the guide with recommendations that help maintainers be proactive in two ways:

• Preventing common vulnerabilities: code analysis, vulnerability scanners, etc.
• Limiting exposure and making it easier to respond to a threat: best practices, dependency management, etc.

This issue comes from our first Docs & Infrastructure Sprint call on Nov 9th.