Idea: Integrate an easy HTML form <-> JSON lib into Shiny aps

[amoeba]

The Shiny apps in #22 are super slick. I think they could be improved with a bit of validation. A common way I'd do this in a web app today would be to use something like react-jsonschema-form (HT @cboettig) to display a form to the user that dynamically updates an underlying JSON model and provides validation.

Definitely a backlog type Issue here but I think it'd be nifty.