AxialGradient type would be helpful #345
Description
I think it would be helpful to blend some types of noise with a gradient.
I have some ideas on how to implement a gradient NoiseFn and i'll probably be doing it for my project, but I'm not sure if the method I have planned would be the most efficient.
I'll share what I end up making? I guess? Maybe I could open a PR? IDRK.