Set up headless Wordpress CMS

## Basic Information
Set up a headless Wordpress CMS backend so that the client can easily edit the content. Useful information [here](https://vercel.com/guides/wordpress-with-vercel).

Rough task list:
- [x] Set up a Wordpress server with Docker (see [official Docker image](https://hub.docker.com/_/wordpress/))
- [x] Dockerise Next.js frontend (see official Next.js Docker examples [here](https://github.com/vercel/next.js/tree/canary/examples/with-docker))
- [x] Set up nginx reverse proxy
- [x] Set up API interface for frontend (e.g. [Wordpress REST API](https://developer.wordpress.org/rest-api/) or [wpgraphql](https://www.wpgraphql.com/))
- [ ] Integrate some frontend pages to query content from Wordpress server
- [ ] Write documentation so others understand how to do this too
- [ ] Implement [ISR](https://vercel.com/guides/wordpress-with-vercel#step-6-incremental-static-page-regeneration-using-getstaticprops) (caching to improve performance)
- [ ] Before merging: check to see if any more documentation needs to be written / updated, and do so
- [ ] Deployment: (will need to be myself or another CFC committee member)
- [ ] Write frontend deployment Dockerfile
- [ ] Set up deployment hosting and CD for Docker

## Other Information