Suppose you have a pdf with 16 pages [1],[2],[3],[4],[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16].
If you run this program, you get a pdf with 8 pages [8|1],[2|7],[3|6],[4|5],[9|16],[10|15],[11|14],[12|13].
If you choose to print this pdf double-sided in landscape format, you get four pages [[8|1]-[2|7]],[[3|6]-[4|5]],[[9|16]-[10|15]],[[11|14]-[12|13]] (on the first page, you will have [8|1] on the front and [2|7] on the back). If you put together the first two pages and the last two pages and fold each of them in the middle, you have two signatures.
If you put the signatures on a deck, you can read the pages in the correct order.
Run
docker build . -t bookbinder
Run
docker run -i -v $(pwd)/test:/mnt/bookbinder bookbinder /mnt/bookbinder
to bind all books in the directory $(pwd)/test.