A baroque method of mapgen to make the village.
Layout is in a checkerboard pattern between a and b tiles.
abababa
bababab
abababa   etc.
It places the mapgen, then overrides with ring chunk, then with core chunk.
Ring chunk a and b's tunnels are basically swatsika- and reverse swatsika-shaped.
The arms line up at the edges to ensure tunnels connect.
Core chunk fills the center and works for a or b.
Edges are just mapgen because chunks can't be rotated.