Add the Countertop

[slifty]

Description

This is a WIP pr.

This PR adds the countertop, which is where appliances are loaded and data is passed to / from them.

Due Diligence Checklist

• [ ] Tests
• [ ] Documentation
• [ ] Consolidated commits
• [ ] Relevant labels assigned

Steps to Test

1. yarn test

Deploy Notes

• { yarn install }
• { yarn migrate }
• { Populate environment variables ... }
• { Set up ... }

Related Issues

Resolves #23 #30

[slifty]

Closing this since it's stale -- will open a new one soon.