Boarding: Taking crew prisoners

[AwesomeDog86]

Instead of crew being killed on boarding, maybe have an option to convert to crew keeping training.

Or have the crew converted into slaves and then make black markets and smuggler outposts buy said slaves.

[Blackhorse_Six_]

I like the first option - it's simple. To anyone who may find it too simple, just reduce the captured/converted crew by some small percentage to reflect those who may have refused to "Join Us" and thus were, uh, repatriated to their own space.