This issue is to track progress on the upgrade from Docusaurus 2 -> 3.
I've done a preliminary manual upgrade for packages in package.json.
The Prism theme has a new method for calling it that I had to fix in docusaurus.config.js.
The site builds, but when serving it locally via yarn start there is still an overlay error for webpack. I'm investigating if it's a show stopper or only a dev thing.