Add a Security Insights file

[matheuscscp]

Security Insights is a specification for communicating security-related data.

For this specific repository, use this example:

https://github.com/privateerproj/privateer/blob/main/.github/security-insights.yml

Resources

Security Insights: https://github.com/ossf/security-insights-spec/

[piontec]

Doing this