Indieweb comment XSS security testing utility

A tool could be made which, given the URL of a post, sends it a webmention with a bunch of XSS attacks in. Each attack, if successful, does a `console.log` call with the name of the vulnerability and a URL with instructions on how to prevent it.

The issue names no implementation files, tests, or entry point. Start by locating how the project handles a post URL and sends webmentions, then define the XSS cases and success reporting described here. Done means a usable utility sends the attacks and reports successful cases with prevention guidance.

Written by the indexing model from the issue text.