Create an example app that uses Origami components

[chee]

We've talked about doing this before, but now the components would all already be in ../node_modules so it wouldn't be the same kind of work to keep it updated.

it can exist for two cool reasons:

1. Serve as an example of how to build an Origami app
2. We can take a screenshot of this app as a smoketest for Percy. Any Pull Request that contains a change to any component can diff the screenshot of the example app and that should help us catch unexpected changes :)

[notlee]

We still want to do this. It's not currently an OKR for this quarter