Adding upcoming books

[PhilippKammann]

My feature idea would be to have the ability to add “pseudo”-books that will release in the future.

Similar to unavailable books, they wouldn't have a file and only exist in the Komga DB, but also not be removed by emptying the trash.

Purpose:
I follow a lot of series, and it's hard to keep track of them all. So, I would regularly check publisher sites to see if there was a new release or if there is one in the coming months.
The upcoming books, I would like to add to Komga, so I can keep track of them, easily notice if a new book was released, and give my users an overview of books that I'm missing.

Example:

• Jellyfin
  

[gotson]

That's not falling in scope of what i envision Komga to do.