Clarify our stance on team supervisors at events

[PeterJCLaw]

Every year we get asked whether or not the person who brings the competitors to our events needs to be a teacher. We don't require this, however we also don't document this anywhere.

We should document (probably on https://studentrobotics.org/docs/robots_101/team_supervisor) what our requirements are so that:

• people will know this ahead of time
• we can point people at it if they ask
• we have a consistent response prepared
• we know exactly what our requirements are

Here's an outline of what I think our requirements are:

• non-competitor
• over 18
• able to be a "responsible adult", responsible for all the competitors at the event
• we know who they are and have at least a mobile number for them
• the primary contact is aware of and happy for this person to be responsible for the competitors, the kit and any equipment they bring
  • and implicitly that the other parents involved are happy