Recipe-scrapers

Adds support for:

- Project Gezond (691)
- Sunset (690)

Thank you, brett NijeboerFrank!

Adds support for:
- 679 - `southerncastiron.com`
- 680 - `handletheheat.com`

Fixes:
- 661 - TypeError on `mob.co.uk`
- 687 - Site updates for `amazingribs.com`

Credits: brett jayaddison

Adds support for:
- creativecanning.com
- lecker.de
- simply-cookit.com

Removes support for:
- sallys-blog.de

Updates a bunch of preexisting scrapers with 676.

Creds vabene1111 hhursev

- Improved author attribution
- scraper for smulweb.nl
- scraper for weightwatchers (offline use)

Creds jayaddison Gittiee-max bickerdyke

Housekeeping / development / maintenance release :broom:

- Introduce `tox` as a standard mechanism to run isolated unit tests and linting workflows (650)
- Introduce `pyproject.toml` for project metadata (655)
- Remove the `test_settings_module` (663)
- Remove `pytest` and `unittest-parallel` development-time dependencies (659, 660, 991b1d1784711bf1276ab74763e4e11c46649ee1)
- Switch unit test scraper setup from per-test-method to per-test-case (668)
- Refactor the `SchemaOrg` parser (671)
- Fixup: incorrect start-URL in scraper test (b5f84adc0cfd2da2d645e43a321b39c7da10d4e8)

This release _should_ have little-to-no effect on usage of the library (it's intended to be backwards compatible) - however, bug / issue reports appreciated, as always!

- Remove `META_HTTP_EQUIV` setting (644)
- Remove `TEST_MODE` setting (645)
- Remove 'v12-like' settings module (653)
- Add omnivores cookbook (647)
- Add maangchi (656)
- Fix justonecookbook (649)

Thank you, wengtad!