need to use symlinks for nested indirection

Git does not like symlinks, however this is the easiest way I can think of to cause nested package.json to be seen as a the package used for resolving "exports". `node_modules/esm-logger/` should be a symlink pointing to `node_modules/logger/esm/` and likewise for `cjs-logger`.

Right now they are raw files and so they don't realpath to `node_modules/logger/esm/package.json` during resolution.