Instance.json schema is not formatted according to spec

Overview:
The Instance.json JSON Schema has the properties precedingTitles and succeedingTitles outside of the properties property. This breaks the schema driven migration tools and likely other schema-based things in the Inventory module

Look at the below screenshot. The properties should be moved into "properties" property

This should be a 2min fix, if not other parts of the code relies on the current schema structure.