Grid Layout Module

This module contains functions for putting a list of diagrams in a grid layout with minimal effort from the user. I find it very useful for comparing diagrams in a more space-efficient way than using `hcat` or `vcat`.
Not really, it only generalises a very specific part of gridCat (so that gridSnake can reverse every other row). And if there's a future reason to export it, it should probably be called something else (puns are fun but not necessarily informative :stuck_out_tongue:).