Manage a book library.

- Group by progress
- Associate any number of ebooks to each book
- Transfer individual books to ereader

# Running

```sh
nix develop --command books
```

# Testing

```sh
pytest
```

# Improvements

- filters:
    - textual search
    https://stackoverflow.com/questions/55828169/how-to-filter-gtk-flowbox-children-with-gtk-entrysearch