[STAR-2263] Initial demo

This MR builds an initial demo application showing off Providence's capabilities.

JIRA tickets: https://tasks.opencraft.com/browse/STAR-2306

Dependencies: None

Screenshots:

Sandbox URL: TBD - sandbox is being provisioned.

Testing instructions:

1. Clone the repository
2. npm install
3. npm run start
4. Play around with the resulting app.

Author notes and concerns:

In order to get this to work, I did have to publish the initial version to NPM (with a few botched tries to start.) Future changes should be able to install from the dist directory after running a build, per the work in this MR.