API edits for consideration

Consider not needing to convert `JSON.stringify(obj)` when passing into #generate.

It looks like #generate was parsing the JSON immediately in any case.

Updated the tests and provided some updates for your consideration if you think this might be helpful.

Next up after playing around with this: Can it be made such that a "random" name only appears once? What is the DSL for that — `{{randomName!}}` and a matcher finds an exclamation mark at the end and know to pop off random values each time they're added?