[css-images-4] HSL in example 16 is incorrect

[megangardner]

https://www.w3.org/TR/css-images-4/#funcdef-conic-gradient

The hsl in this example should be hsl(0,0%,75%), as 0 in this gradient is 3/4ths of the way between black and white.

[tabatkins]

Thanks for pointing this out!