Add CI test and deploy

[Decipher]

Is your feature request related to a problem? Please describe.
As a maintainer I want the demo site to test and deploy via continuous integration, because it reduces the work I need to do to maintain the project.

Describe the solution you'd like

• Add Test workflow
• Add Build workflows: Staging / Production / Feature?
• Add Unit tests #4
• Add Cypress tests #5

Describe alternatives you've considered
N/A

Additional context
Site is serverless and only needs to deploy statically generated content.
Site is hosted on Netlify.

[Decipher]

Used a Build Test Deploy workflow based off https://github.com/Decipher/stuar.tc/blob/develop/.github/workflows/ci.yml