Security Considerations section

[simoneonofri]

• Introduction
• Threats (Web API Level)

[npdoty]

Is this the same issue as #184? Or was this "WIP" intended to be a work in progress pull request?

[simoneonofri]

@npdoty I wanted it to be the text or at least part of the threats. I'm figuring out how to better structure things on GitHub :)