Django-ninja-crud

Added
- support `int` primary key. (14)
- allow testing `limit` and `offset` pagination parameters. (18)

Changed
- removed `.dockerignore`, `Makefile` and `poetry.lock` files. (20)
- changed `filters` type of `ListModelViewTest` class to `Payloads`. (16)

Fixed
- updated `README.md` (13, 21) and the [documentation](https://django-ninja-crud.readme.io/).
- added `django` and `django-ninja` version matrix for tests workflow. (8)

Added
- Added `filters` attribute to `ListModelView` class. (5)

Changed
- Renamed `is_instance_view` to `detail`. (7)
- Made `credentials_getter` optional for every test classes.

Fixed
- Addressed all areas of the codebase that were missing test coverage. The project now has 100% test coverage.