bitsandbytes authors (NF4 quantization kernels)

Tim Dettmers <dettmers@cs.washington.edu>  — original author and lead
The bitsandbytes contributors                — see upstream `AUTHORS` /
                                              git log at
                                              https://github.com/bitsandbytes-foundation/bitsandbytes

The NF4 (NormalFloat 4-bit) format was introduced in:

  Tim Dettmers, Artidoro Pagnoni, Ari Holtzman, Luke Zettlemoyer.
  "QLoRA: Efficient Finetuning of Quantized LLMs." NeurIPS 2023.
  arXiv:2305.14314.

The 16-entry NF4 codebook constants reproduced in baracuda's vendored
launcher header derive from the NF4 paper's inverse-CDF-of-Normal
construction (see Section 3.1 of arXiv:2305.14314), and are bit-identical
to the constants used by upstream bitsandbytes.
