Add a primaryColorShade theme property

[empz]

When adding a new color using the generator, the tool will automatically decide where in the shade the base color is. That's okay, but it also means that a button primary will have the base color as the primary, but a different shade.

Take this color for example: https://mantine.dev/colors-generator/?color=983fff

I want the button (and every other component that has a color) to use this primary color, but the shade 4. Setting primaryShade: 4 in the theme changes the default shade for ALL colors, which is very inconvenient. I thought the primaryShade would only affect the primaryColor, but that's not the case. I think there should be a way to change the primaryShade only for the primaryColor. Maybe a new theme prop like primaryColorShade.

[haltcase]

It would be great to be able to specify primary shades for each individual color, defaulting to the global primaryShade if unspecified. Some of my colors are just too light or dark to put them at the same index as our primary color's default shade, and now I have to remember to specify the shade for those colors every single time I use them, e.g., color.5.