The note renderer has been moved back to the main repository, to make development easier:
The way it was setup in a separate repo was complicated and I assume would discourage contributions (including my own). Now it’s possible to simply make a change to the renderer, and see the result directly, without any complicated build step.
The advantage is that it will also benefit from the existing tooling, including eslint and TypeScript.
The renderer can still be compiled to a self-contained renderer though and thus can be used in projects outside of the main Joplin apps (the goal eventually is to use that renderer in the Joplin Web API for Nextcloud).