As an organizer, I want to know what information is collected on participants if I enable registration, so that I can properly informed of the behavior of event registration and make the choices that are best for me.
Acceptance Criteria:
- Add the following text: "Only usernames will be collected from participants during registration. Learn more."
- The "Learn more" link should link to documentation for the tool on Mediawiki.org
- Note that this messaging will change when we begin to collect more user information in V2
Visual example: