Sunset this repository in favour of commercejs-nextjs-demo-store

[robbieaverill]

This repository was originally created as a copy of https://github.com/chec/commercejs-nextjs-demo-store. It has some different products in it, and the readme is focussed around deploying it to Vercel rather than Netlify.

We want to sunset/archive this repository and focus on the other one, which can be configured to deploy to both Vercel and Netlify.

Tasks:

• Make https://github.com/chec/commercejs-nextjs-demo-store deployable to Vercel
• Update readme in that repo so the deployment instructions are clearly separated for each provider
• Add build badge for Vercel deployment status to that repo
• Archive this repo