Feature request: add local storage in addition to uploading files or using Dropbox for self-hosting

[ovizii]

So if I self-host it behind authentication, and it does not yet support getting books from an OPDS feed, I don't want to manually upload my books or use Dropbox. How about adding support for local file storage, local to where flow is deployed, i.e. by using a docker volume mapping?

This way, I could just map my e-book storage path into this container and keep reading from any device without moving my e-books anywhere.