More-itertools

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* New functions
* The :func:`subslices` recipe from the `itertools` docs was added (thanks to rhettinger)

* Changes to existing functions
* The :func:`ichunked` function is now more efficient (thanks to hjtran0 and seanmacavaney)
* The :func:`difference` function is now more efficient (thanks to Masynchin)
* The :func:`grouper` recipe now has more features, mirroring the one in the `itertools` docs (thanks to rhettinger)

* Other changes
* Some documentation issues were fixed (thanks to medvied and Freed-Wu)
* The `more_itertools` package is now built with `flit` (thanks to mgorny)

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* Bug fixes
* Some documentation issues were fixed (thanks to Masynchin, spookylukey, astrojuanlu, and stephengmatthews)
* Python 3.5 support was temporarily restored (thanks to mattbonnell)

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* New functions
* The :func:`before_and_after`, :func:`sliding_window`, and :func:`triplewise` recipes from the Python 3.10 docs were added
* :func:`duplicates_everseen` and :func:`duplicates_justseen` (thanks to OrBin and DavidPratt512)
* :func:`minmax` (thanks to Ricocotam, MSeifert04, and ruancomelli)
* :func:`strictly_n` (thanks to hwalinga and NotWearingPants)
* :func:`unique_in_window`

* Changes to existing functions
* :func:`groupby_transform` had its type stub improved (thanks to mjk4 and ruancomelli)
* :func:`is_sorted` now accepts a ``strict`` parameter (thanks to Dutcho and ruancomelli)
* :func:`zip_broadcast` was updated to fix a bug (thanks to kalekundert)

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* Changes to existing functions
* The type stub for :func:`iter_except` was improved (thanks to MarcinKonowalczyk)

* Other changes:
* Type stubs now ship with the source release (thanks to saaketp)
* The Sphinx docs were improved (thanks to MarcinKonowalczyk)

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* New functions
* :func:`interleave_evenly` (thanks to mbugert)
* :func:`repeat_each` (thanks to FinalSh4re)
* :func:`chunked_even` (thanks to valtron)
* :func:`map_if` (thanks to sassbalint)
* :func:`zip_broadcast` (thanks to kalekundert)

* Changes to existing functions
* The type stub for :func:`chunked` was improved (thanks to PhilMacKay)
* The type stubs for :func:`zip_equal` and `zip_offset` were improved (thanks to maffoo)
* Building Sphinx docs locally was improved (thanks to MarcinKonowalczyk)

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* New functions
* :func:`countable` (thanks to krzysieq)

* Changes to existing functions
* :func:`split_before` was updated to handle empty collections (thanks to TiunovNN)
* :func:`unique_everseen` got a performance boost (thanks to Numerlor)
* The type hint for :func:`value_chain` was corrected (thanks to vr2262)