Dj-angles

- Self-closing `dj-block` tag; `<dj-block name='content' />` would translate to `{% block content %}{% endblock content %}`.
- Handle template includes that begin with an underscore; `<dj-partial />` would translate to, in order, either `partial.html` or `_partial.html` depending on which template file was found.

- Use the start tag's `name` for `dj-block` end tag if possible.

- Add `default_mapper` based on [7](https://github.com/adamghill/dj-angles/pull/7) from [nanuxbe](https://github.com/nanuxbe).

- Add (beta) named slots implementation. Enable with `ANGLES={"enable_slots": True}` in settings.
- Fix: End wrapping tag was sometimes incorrect for some includes.

- Create tag mappers once and cache it.

- Add integration with [`django-bird`](https://django-bird.readthedocs.io/).

**Breaking changes**

- Dropped support for Python 3.8.