Add Development Plan text to Members

[ardalis]

I want to have a place to discuss and review a personal development plan with members. Having it in their devBetter profile as an admin-only view item seems like it makes the most sense. I'm not 100% sure whether it should allow editing by the member all the time, but it's probably fine for them to be able to add the initial version, or at least edit it until we review it and lock it in.

Alternately, it could be a series of dated entries, which could include 1:1 touch points with me over time. Past entries would be immutable, perhaps locked 24 hours after they're added, so that they can be edited initially. I think I prefer this approach.