Set up with schemasheets

[caufieldjh]

When these schemas were still getting assembled, I attempted to translate them to schemasheets - this did not go as well as expected, likely because the data model was still incompletely defined. If we can translate the current version to GSheet and sync w/COGS then we may be able to update the model more smoothly (i.e., without needing to update the YAML schema directly).