Example documentjs.json files.

We should try to have only one place in the API docs that shows example `documentjs.json` files. All other pages should basically say things along the lines of

> "make sure your documentjs.json is in place. Refer to [the configuration page](http://documentjs.com/docs/DocumentJS.guides.configuring.html) for examples."

Start with the API documentation and the linked configuration page at documentjs.com/docs/DocumentJS.guides.configuring.html. Find the pages that currently show example documentjs.json files, consolidate those examples on the configuration page, and replace other examples with references to it. Done means the configuration page is the single example location and other pages point readers there.

Written by the indexing model from the issue text.