- rename hardware.opengl to hardware.graphics
- remove hardware.opengl.driSupport, which does nothing
- remove hardware.opengl.setLdLibraryPath, which should never be done
- rename hardware.opengl.driSupport32Bit to hardware.graphics.enable32Bit
- lost of small docs / formatting cleanups
`beignet` saw no development since 2018 and was never ported from
`llvmPackages_6`. Is it's a library to support `OpenCL` on older GPUs
let's drop it from `nixpkgs`.