Create security.md file

[kornys]

Pull Request Template

Description

Community standards suggest to create security file in root repository where we inform how to report sec issue and what version we patch etc...

Type of Change

Please delete options that are not relevant.

• Documentation update

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit/integration tests pass locally with my changes