Add section about combining code from arrow and dbplyr with a complex query

[ddotta]

However, for a simple query like this, it is hard to see the benefit of combining with the arrow package from the dbplyr side, so it might be more easier to understand if explaining that arrow and dbplyr support a different range of R functions inside dplyr.

https://github.com/ddotta/cookbook-rpolars/pull/13#pullrequestreview-1520669780