Itemloaders

- Fixed an error when using nested loaders with empty matches that was introduced in 1.3.0

- Added support for method chaining to the `add_*` and `replace_*` methods
- Added type hints and `py.typed`
- Made the docs builds reproducible

- Added official support for Python 3.12 and PyPy 3.10
- Removed official support for Python 3.7
- Improved performance of ``itemloaders.utils.arg_to_iter``
- Fixed test expectations on recent Python versions
- Improved CI

- Added JMESPath support (`ItemLoader.add_jmes` etc.), requiring Parsel 1.8.1+
- Added official support for Python 3.11
- Removed official support for Python 3.6
- Internal code cleanup
- Added ``pre-commit`` support and applied changes from ``black`` and ``flake8``
- Improved CI

Fixes a regression introduced in 1.0.5 that would cause the `re` parameter of `ItemLoader.add_xpath` and similar methods to be passed to lxml, which would trigger an exception when the value of `re` was a compiled pattern and not a string (56).

- Allow additional args to be passed when calling `ItemLoader.add_xpath` (48)
- Fixed missing space in an exception message (47)
- Updated company name in author and copyright sections (42)
- Added official support for Python 3.9 and improved PyPy compatibility (44)
- Added official support for Python 3.10 (53)