Add Security.md policy page

[artem-smotrakov]

The process of reporting security issues should be documented and easy to find.

I'd like to propose adding a security policy to the project that would be integrated with other GitHub features

https://docs.github.com/en/free-pro-team@latest/github/managing-security-vulnerabilities/adding-a-security-policy-to-your-repository

I think SECURITY.md would make it a bit easier to find the docs that describe how security issues should be reported.

[stleary]

What problem does this code solve?
Making it easier to people to report security problems

Risks
N/A

Changes to the API?
N/A

Will this require a new release?
No

Should the documentation be updated?
This is the documentation

Does it break the unit tests?
N/A

Was any code refactored in this commit?
N/A

Review status
APPROVED

[stleary]

Since there are no Java file changes, the comment window is not needed.