Add Dockerfile

[andyyPark]

Addresses #88 - it's using tensorflow-gpu as the base image (it doesn't work on arm64 processor at the moment).

To build the docker image manually, run:

docker build -t jax_cosmo .

To execute jax_cosmo in a jupyter notebook within the docker image:

• Host machine: docker run --rm -it -p 8888:8888 jax_cosmo
• Inside the container: jupyter notebook --ip 0.0.0.0 --port 8888 --no-browser --allow-root
• Access the notebook on : localhost:8888