nsls2/nsls2forge repository overview

Based on https://github.com/conda-forge/docker-images/blob/master/linux-anvil-comp7/Dockerfile⁠, but we have to remove /opt/conda/.condarc as it comes from https://github.com/conda-forge/miniforge/blob/master/Miniforge3/construct.yaml⁠.

See https://github.com/conda-forge/docker-images/pull/142⁠ for details.