Coloraide

- **NEW**: Add new RYB color space.
- **NEW**: Add `Regular` mixin class for normal, 3 channel color spaces (sRGB, CMY, RYB, etc.).
- **NEW**: `harmony()` can now accept and transform `Labish` and `Regular` color spaces to cylindrical spaces.

- **NEW**: Add `padding` parameter to limit color scales when interpolating.

- **NEW**: Add new `discrete()` function that creates a discrete interpolation object.
- **NEW**: Deprecate `coloraide.algebra.apply` function in favor of new vectorize functions.
- **FIX**: Fix small typing issue.
- **FIX**: Tweaks to Oklab 64 bit matrix precision.
- **FIX**: Fix `prismatic` and `cmyk` achromatic check logic.
- **FIX**: Ensure IPT uses the exact white point as documented in the paper.
- **FIX**: Fix various corner cases of algebraic functions and implement some performance improvements.

- **NEW**: Add Rec. 709 RGB color space.
- **NEW**: Add the 1960 UCS color space.
- **NEW**: Add correlated color temperature support with new `cct()` and `blackbody()` API.
- **NEW**: Add support for Robertson 1968 and Ohno 2013 CCT plugins.
- **NEW**: Add support for determining if a color is in the Pointer Gamut and provide a way to clamp a color to the
gamut.
- **NEW**: Include CMFS: CIE 1931 2 Degree Standard Observer, CIE 1964 10 Degree Standard Observer, CIE 2015 2 Degree
Standard Observer, and CIE 2015 10 Degree Standard Observer.
- **NEW**: Add `split_chromaticity()` method which will split a color into its chromaticity and luminance parts.
- **NEW**: Add `chromaticity()` which will create a new color from a given set of chromaticity coordinates.
- **NEW**: Relax `chromatic_adaptation()` type requirement of white point chromaticity inputs.
- **NEW**: `luminance()`, `xy()`, and `uv()` all now accept an optional white point via the `white` parameter to
control the white point in which the returned values are relative to. `luminance()` still defaults to D65 but will
use the current color's white point, like `xy()` and `uv()` if `white` is set to `None`.
- **NEW**: `white()` now accepts a positional parameter allowing it to output the white point of the current color
as various chromaticity coordinates in addition to the default XYZ coordinates.
- **FIX**: Fix case where deregistering all plugins with `*` was not deregistering `Filter` plugins.

- **NEW** ACEScc will now resolve undefined color channels (non-alpha) with a non-zero default that represents black for
consistency with other ACES color spaces.
- **ENHANCE**: Streamline averaging algorithm to increase performance.
- **FIX**: Ensure that HCT consistently clamps negative lightness and chroma to zero.

- **FIX**: Improve HCT round trip conversion speed and improve conversion in some weak areas.