v1.0.0 spring cleaning

[thibaudcolas]

Must Thibaud:

• Add Code of conduct
• Add Security policy
• Add maintainer names either via pyproject.toml or CODEOWNERS (or both)
• Update maintainers documentation
• Set up Code scanning alerts
• GitHub CodeQL
• Add -X dev -W error flags to test suite
• Add to https://djangopackages.org/
• Add to https://github.com/wsvincent/awesome-django
• Development Status :: 5 - Production/Stable trove classifier
• Fix or discard LGTM security report
• Open / advertise GitHub Discussions
• Add "Discussions" link in PyPI sidebar
• Add "Demo" link in PyPI sidebar
• Add "Support" / "Help" page in docs
• Review recent internal discussions & update docs
• Create/update public list of projects using this in production in README (https://torchbox.github.io/django-pattern-library/reference/related-projects/#pattern-libraries-based-on-django) (https://github.com/pyatl/big-peach)

Maybe Ben:

• Add type hints for public API #172
• CI builds caching / speed optimisations #181

Maybe Thibaud:

• Docs linting: Markdown syntax, spelling
• Upgrade to Webpack 5 & external CSS file #183

Maybe Thibaud & Ben:

• Jinja2 support plan #171
• Demo / document setup with https://github.com/mixxorz/slippers, or https://pypi.org/project/django-components/, or https://pypi.org/project/django-component/