re-focus content about schema validation

[monkeypants]

In the schema validation section, I think it is safe to assume that some readers will already know how to validate a json schema; Maybe a detailed description of one tool (with screen shots) is disproportionate. Perhaps suggesting particular schema validation tools (or where to find) them could be more compact and expressive, e.g. a link to an addendum that lists some free json schema validation tools.

A diagram (e.g. UML class or entity-relationship) illustrating the logical parts of the schema might be helpful. Especially if it accompanied text describing purpose of the parts of the overall logical model.