Add endpoints for book's bookmarks #14
Description
Add:
- POST /api/v1/books/{id}/bookmark for creating new bookmark for the book
- GET /api/v1/books/{id}/bookmark for listing all available book's bookmarks with pagination
- PUT /api/v1/books/{id}/bookmark/{id} for updating book's bookmark
- DELETE /api/v1/books/{id}/bookmark/{id} for deleting book's bookmark