Create a Security Policy

[joycebrum]

Changes

Closes #221

• Create the security.md file with a standard body

It needs yet a security email to gather possible vulnerabilities reports.

I've proposed this vulnerability disclosure timeline but let me know if you are more confortable with a different one.

PS: the Security Advisory is a github tool to Vulnerabilities Disclosures (I've seen you've already familiar with it).

Besides that feel free to edit or suggest any changes to this document, it is supposed to reflect the amount of effort the team can offer to handle vulnerabilities.

[joycebrum]

Another option is to use the github advisories to receive vulnerabilities reports, if you rather I can update the doc to mention it instead of emailing. But it need to be enabled and it is in beta yet.

https://docs.github.com/en/code-security/security-advisories/guidance-on-reporting-and-writing/privately-reporting-a-security-vulnerability