Request to add language as an attribute for each book.

[adityasharat]

#13 already addresses this, but haven't seen any updates on that for a while. If language can be added in the interim, I think it would be helpful to at least some people. Also, it wouldn't take too much time to implement it.
I could raise a PR with language added as an attribute to each book. ex.

{
  "lang": "en"
}

[ShalokShalom]

Yes. +1

[deka]

Hi
Can you also add date ?