Fix embedded population. Check if doc already transformed.
Attachment to root now in it's own function.
Remove optional filters in populatePaths. This actually makes more sense.
Extract populatePaths into it's own plugin.
Fix. No longer use cached populated ids, they aren't within scope.
Rename populatePaths to recursePaths.
Add notes regarding pre-transformed synchronous objects.
Polymorphic sideload references fixes!
Fix pre-transformed objects, by supporting `id` as a ref.