Set up Spack for building ACCESS models on NeSI HPC

Technical spack
1

Set up Spack for building ACCESS models on NeSI HPC (v1)

git clone https://github.com/ACCESS-NRI/spack.git --branch releases/v1.1
git clone https://github.com/ACCESS-NRI/spack-config.git --branch development-nesi
ln -s -r -v spack-config/v1.1/nesi/* spack/etc/spack/
. spack-config/spack-enable.bash