Hi. I’m new to chicken keeping and I’m wondering how many chickens I can keep in my coop? It measures 12x4x8 with the indoor area being about 4x4. It is actually built using the plans for Heather Bullards coop. I also have a large fenced area outside of it for them to wonder into. Just want to be sure i don’t overcrowd theM while inside at night. I plan to get a mix of regular size and silkie chickens. Thanks in advance.