Add compute shader to API

[gehrigwilcox]

I want to use compute shaders and I see the game of life example but it seems to be using internal code rather than API calls which means that you can't use compute shaders through any language bindings.

I can help create this, I just want to make sure that

a. There isn't already a way to use compute shaders with raylib in other languages (such as go)

b. The proposed API calls fit in the ecosystem