Create defined YML schemas for "ontologies"

[RobertLRead]

We have a pressing need now for loosely compuled "ontologies" which we can develop. At one level, there will be simple lists. We really need a dictionary of "tooling" and "products" (ouputs of an OKH) and "bom parts" (inputs to an OKH.) This will get complicated, but if we just create and start expanding ontology documents here, we will have made excellent progress. We need both a schema (I'm not a YML schema expert) and the actual data/instance files.