Support Crew: higher expectations of Senior SEs

Problem

We haven't defined any different role for Senior SEs on Crew days, and so we're possibly not having them work to the best advantage of the team and the customers.

Request

Lee to discuss the problem with other managers, SEs, etc., and to update the handbook with clear guidance.

Initial thoughts as to what we might change for Senior SEs:

1. Set the expectation that they should be present, visible, active and proactive throughout their Crew day
2. Set the expectation that they should be thinking and acting as leaders within their Crew
3. Set the expectation that they should be sharing knowledge with the Crew, and helping and encouraging the other Crew members to do the same