My villager breeder here makes use of villagers wanting to feed each other. I don't remember where I got this from but it was from some youtuber out there, somewhere... Anyways, the first photo is the basic design layout for the farming villager to gather up crops to then drop onto 2 villagers. The second photo shows the two villagers waiting to be fed with 4 beds surrounding them. This means that they can sleep and when they breed they check for open beds so the kid can sleep somewhere. The baby then drops down into a water collector and the minecart can then pick up the baby.

The redstone part starts here. Once the baby villager is inside the minecart, there is a tripwire that is looking for anything that will trip it and open up the piston block wall thingy. So, once the baby villager is an adult, the piston gate opens and dispenses another minecart that the villager is then transferred into to then be brought to a small building for me to give them a job and trades that I like. They are then brought to another building with a whole bunch of other villagers to be further traded with for future emerald gains.

Underneath the water I have a collection system to collect carrots that are missed by the villagers. Although, looking at the photo I realized that the carrots will never be picked up because the hopper underneath won't collect items without a mincart on top. So I need to remake the carrot collection but that's an easy fix.