Describe programs, running them, errors, threads and systems
Programs covers define-program, compile-program, what a compiled program
tells a GPU layer, the device features, looking inside a stage, and
redefinition. Running on the GPU computes, draws, packs uniforms every
frame and samples a texture with cl-gfx, offscreen. Errors lists every
condition, what each says and Lisp's own type errors; Threads says what
may be shared and what allocates every frame; Systems gives the systems,
the packages and cl-gmath in shader code. The API Reference lists every
exported symbol of clsl, clsl/vulkan and clsl/gmath.
