read_dir: Read a directory of returns data
In MEDSL/medslcleaner: A MEDSL Package for Cleaning Election Returns

A wrapper for the pattern:

1	read_dir(path = "../raw", f = data.table::fread, idcol = "path", ...)

`path`	Path to a directory of returns.
`f`	A function for reading files from disk.
`idcol`	A name for the column in the result giving file paths.
`...`	Further arguments to `[list.files]`.

Locate paths with base::list.files(), using full.names = TRUE and perhaps a pattern
Apply a read function like data.table::fread() or readxl::read_excel() to each path
Combine the data with e.g. data.table::rbindlist(), using the paths as an identifier column