Not sure if this was already mentioned but IMO it would be really helpful if a taxonomy could be added to it, so it would be easier to find related books with a

Not sure if this was already mentioned but IMO it would be really helpful if a taxonomy could be added to it, so it would be easier to find related books with a certain subject. (e.g. 'economy', 'data science' or 'distributed physics'). It would also open up the possibility of faceted search (e.g. all books on 'data science' with the 'python' programming language). Other than that this already looks pretty useful :)