This project makes use of npm workspaces.
In the project root, run:
npm i
This will install all dependencies for all workspaces. No need to install in any subdirectories.
To watch changes in source code for specific packages (e.g. core and server), run:
npm run dev core server
When you make changes to these package's source code, Rollup will notice and re-bundle them.
Then navigate to an example project and run the npm run build or npm run dev commands as per usual. Example project dependencies will automagically be imported from the relevant package workspace, removing the need for npm link.
If you are working with a site outside of a workspace, then you'll still need to npm link. Make sure you're using the same Node version in the terminal windows you use since npm link works by symlinking to specific Node versions.