Include example with flights data

[hadley]

Maybe provide some helper function to get it:

base_url <- "https://blobs.duckdb.org/flight-data-partitioned/"
files <- paste0("Year=", 1987:2024, "/data_0.parquet")
for (dir in dirname(files)) dir.create(dir, showWarnings = FALSE)

out <- curl::multi_download(paste0(base_url, files), files, resume = TRUE)

And then show how you can easily work with a large data set.