ref https://linear.app/tryghost/issue/DEV-20/faster-builds
- `build` should be the overall script to build the package
- `build:ts` should only build TypeScript
- by having them switched around, `build:ts` would call `yarn build`,
and `yarn` adds several hundreds of milliseconds of time to each build
- this version is written in TS, but was published a few months ago and
needs to be bumped here
- also updates a previous deep include into the library, which was
unnecessary anyway
refs https://github.com/TryGhost/DevOps/issues/45
- this switches the monorepo over to using Nx instead of Lerna, because
we don't currently need the versioning+publishing capabilities
- this also adds an `nx.json`, which allows us to enable task caching
- also adds `build:ts` to the TS projects, which is cached for fast execution
- how these interact with the dev.js script will hopefully soon be
reworked to be a better experience
