Add new linear interpolation methods for ``quantile`` and ``percentile``
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``quantile`` and ``percentile`` now have 13 linear interpolation methods,
nine of which can be found in the scientific literature.
The remaining methods are NumPy specific and are kept for backwards
compatibility. The default is "inclusive" (method 7), whose behavior is equivalent
to the former default "linear".

Add new methods for ``quantile`` and ``percentile``
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``quantile`` and ``percentile`` now have have a ``method=``
keyword argument supporting 13 different methods.
This replaces the ``interpolation=`` keyword argument.

The methods are now aligned with nine methods which can be
found in scientific literature and the R language.
The remaining methods are the previous discontinuous variations
of the default "linear" one.

Please see the documentation of `numpy.percentile` for more information.

Add release not for quantile `interpolation` rename
DOC: Add release not for quantile `interpolation` rename

Also updates the old release note to include the info (and generally
tweaks it a bit)
