Implement :onyx/n-peers as a simile for :onyx/min-peers = :onyx/max-peers

[lbradstreet]

This could probably be done pretty easily by expanding out :onyx/n-peers to :onyx/min-peers and :onyx/max-peers in the relevant place.

@MichaelDrogalis how do you feel about this one? It might not be worth the hassle, but :onyx/n-peers might make it a bit more obvious that you can set the number of task peers to a particular number.