Django-content-settings

* remove `urls.py` now the only quick way to connect API is to use [Views](api.md)
* remove `content_settings.startswith` and `content_settings.withtag`
* more [doc-strings](source.md), update `poetry.lock` and test coverage 94%

* fixing nox testing for covering different Python and Django versions
* `context_managers.context_defaults` moved to `defaults.context.defaults`. More in [defaults documentation](defaults.md)
* `CONTENT_SETTINGS_DEFAULTS` is a replacement for `CONTENT_SETTINGS_CONTEXT_PROCESSORS` and `CONTENT_SETTINGS_CONTEXT`. More in [defaults documentation](defaults.md)
* Ability to assign defaults globally for specific setting types. More in [defaults documentation](defaults.md)
* `CONTENT_SETTINGS_ADMIN_CHECKSUM_CHECK_BEFORE_SAVE` - new settings that makes sure that nothing is changed while the Django Admin panel for content settings were opened
* remove overwriting default attributes tags and permissions in subclasses.
* new module [functools](functools) - which now contains logical functions `not_`, `or_` and `and_`, moved from module `permissions` since those functions are used for `defaults.filters` as well
* [Preparation for the version 1](https://github.com/occipital/django-content-settings/labels/v1)

* `SimpleExec.call_return` and `DjangoModelTemplateMixin.model_queryset` can be callable now
* `mdsource` for generation docs from the source code
* black version was updated to use for Python 3.8

* `CONTENT_SETTINGS_TAGS` refactoring, the function accepts additional argument name
* `"content_settings.tags.app_name"` - autogenerate tag with the app name
* new validators `gen_call_validator`, `gen_args_call_validator` and `gen_kwargs_call_validator`
* AttributeError when you trying to use an uknown setting name

* 📖 SimpleExecNoCall
* 📖 GiveOneKeyMixin
* 📖 SimpleExecOneKey
* 📖 SimpleExecOneKeyNoCall
* STATIC_INCLUDES.UNITED_SETTINGS

* internal constants refactoring to Enums.
* validation changes on the list view using `content_settings_context`
* Admin: fix delete link