Allow IDE autocomplete for Exemplar config files

### 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](http://schemastore.org/json/) 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.

The issue does not name implementation files or tests. Start by locating the sample.conf format and reviewing the suggested JSON Schema Store approach; done means users can discover available properties and values through IDE autocomplete.

Written by the indexing model from the issue text.