Feature Request: OPDS Support

OPDS (Open Publication Distribution System) is a family of specifications dedicated to the distribution of digital publications.

OPDS support consists of:

1. Browsing of books as per the OPDS standard.
2. Searching of books as per opensearch standard.

There is some starting documentation on OPDS at http://www.feedbooks.com/api/primer, and the spec is at https://specs.opds.io/

related golang projects that might be of help: https://github.com/dubyte/dir2opds, https://github.com/opds-community/libopds2-go

The 2.0 spec supports JSON, but no client support exists for it yet.