Bookshelves #465
Description
I think the app would really benefit from one higher level of organization for texts (e.g. bookshelves).
Currently there is just one big Library. For example, I like to read novels, news articles, and blog posts. I'd like to be able to organize them all onto their own "bookshelves". Otherwise I'm limited to importing every text with some kind prefix (e.g. "News:" for news articles), so I can find them all in the Library search.
I'm imagining each "Bookshelf" as basically the same thing as the current "Library" where the current library is just the default "Bookshelf". And then an additional page where bookshelves can be created/deleted/managed.
This features would also be a good abstraction to allow sharing of collections of texts per issue #420.