Add MacOS-specific install instructions (#463)
Add MacOS-specific install instructions (#463)


lorenzoalfieri/atom-molecule-dev-environment,lorenzoalfieri/atom-molecule-dev-environment,alanzanattadev/atom-molecule-dev-environment,alanzanattadev/atom-molecule-dev-environment,lorenzoalfieri/atom-molecule-dev-environment,alanzanattadev/atom-molecule-dev-environment