Django-safe-template-engine

- Small fixes in changelog and README

- Lower Django version requirement to 3.0
- Lower Python version requirement to 3.7
- Add official support for Django 3.0 to 5.0 with:
- Addition of automated test coverage
- Review of all the built-in template tags and filters
- Add support for Django 5's `escapeseq` filter
- Use [tox](https://tox.wiki/) to manage test suite environment

- Add official support for Python 3.12
- Reformat source code with with [black](https://pypi.org/project/black/)
- Set up project for PyPi release
- Update `pyproject.toml` with build system and other details for PyPi
- Add contributing guidelines to `README.md`
- Add `.git-blame-ignore-revs` with revisions to ignore in `git blame`
- Sort filters by alphabetical order in the documentation and source code

- Add official support for Django 3.2:
- Use Django 3.2 in automated tests
- Review all the Django 3.2 built-in template tags and filters (no changes needed)
- Drop official support for Django 3.0 (still unofficially supported in this version as there are no breaking changes)
- Remove Python 3.7 from supported versions in `pyproject.toml` (never officially supported)
- Start keeping a changelog in `CHANGELOG.md`

- Review all the Django 3.0 built-in template tags and filters:
- Allow the ones considered safe
- Make sure the rest is forbidden with technical test coverage
- Add official support for Python 3.8 to Python 3.11 (covered by automated tests)
- Add official support for Django 3.0 (covered by automated tests)