Missing nycflights13 citation

```bibtex
@Manual{Wickham2022NYC,
  title = {nycflights13: Flights that Departed NYC in 2013},
  author = {Hadley Wickham},
  year = {2022},
  note = {R package version 1.0.2},
  url = {https://github.com/hadley/nycflights13},
}
```