Although Itch doesn't have book options, it does allow you to upload (and even sell) files as PDFs or epubs or similar. So yes, you can upload books or written stories. The big problem will be connecting with users who only want books and not a game.
I would recommend that you follow some Twine tutorials, it's a web tool to create interactive stories in a simple way and then you can publish them on Itch, there are many people who do that and you will be able to find players on Itch who are interested in this type of interactive stories much easier than it would be to find someone who only wants to read a PDF book.