TIL about the bulk import functionality in django-import-export library.
https://django-import-export.readthedocs.io/en/latest/bulk_import.html
Some caveats:
- set `batch_size` for better performance
- doesn't work with many-to-many relationships
- no `pre_save` and `post_save` signals sent (it' doesn't call `model.save()`)
