Allow IDE autocomplete for Exemplar config files

[eriwen]

Expected Behavior

As a user, I want to more easily author my sample.conf files by leveraging autocomplete

Current Behavior

No completion available

Context

It's not obvious what properties and values are available. Better to use something like JSON Schema Store or a similar mechanism to allow completion through IDEs. Though there are not very many Exemplar users yet, all of them are likely to want this feature.