Adds Nvidia/OpenGL support to other docker builds.

Requires nvidia-container-toolkit: "https://github.com/NVIDIA/nvidia-docker"

-- USAGE

Build: docker build <PATH_TO_DOCKERFILE_DIR> --build-arg from=<BASEIMAGE> -t <BASEIMAGE>:opengl

Run: docker run -v /dev/:/dev --runtime=nvidia -e NVIDIA_DRIVER_CAPABILITIES=graphics <BASEIMAGE>:opengl