feat: Add JAX Docker image and hello world example

[matthewfeickert]

• Add nvidia/cuda:11.6.0-cudnn8-devel-ubuntu20.04 based pyhf + JAX Docker image with pyhf v0.7.0 and JAX v0.3.25.
  • This should eventually be ported to https://github.com/pyhf/cuda-images but this will require some reworking of the build procedure there.
• Add noxfile with build and test sessions for the Docker image.
• Add "chtc_hello_gpu" example for HTCondor submission to request GPUs.
  • This is a copy of https://github.com/CHTC/templates-GPUs's "hello_gpu" example modified for the pyhf image.
• Add summary information to README

* Add nvidia/cuda:11.6.0-cudnn8-devel-ubuntu20.04 based pyhf + JAX
  Docker image with pyhf v0.7.0 and JAX v0.3.25.
   - This should eventually be ported to https://github.com/pyhf/cuda-images
     but this will require some reworking of the build procedure there.
* Add noxfile with build and test sessions for the Docker image.
* Add "chtc_hello_gpu" example for HTCondor submission to request GPUs.
   - This is a copy of https://github.com/CHTC/templates-GPUs's "hello_gpu" example
     modified for the pyhf image.
     c.f. https://github.com/CHTC/templates-GPUs/tree/a3f7357b633743c96817a92b9f096e2d5db37146/docker/hello_gpu
* Add summary information to README