Create a sample JSON object for the rivers example's form

[stevenday]

Based on the data structure we're already using, and using the backbone-forms project: https://github.com/powmedia/backbone-forms we need to create a JSON object that defines the form(s) for the rivers example. Probably best to start with a simple aspect of it (the first page) and then expand from there.

[stevenday]

This is available inside index.html - though it only defines the data for site 1 and numeric fields at the moment, the rest will be easy to follow using backbone-forms documentation.