Add chests

Store your items, uses:
https://github.com/deathcap/voxel-chest
https://github.com/deathcap/voxel-blockdata
Increase home position Y coordinate
Increase block ID size to 16-bits

Can go up to 32-bits with Uint32Array, but not sure if that much is
needed. Increased from 8 to 16-bits to make room for future expansion,
testing with it now to uncover any performance impact problems.