Update homebrew instructions in README
Update homebrew instructions in README

crchemist/scioncc,crchemist/scioncc,ooici/pyon,mkl-/scioncc,mkl-/scioncc,ooici/pyon,scionrep/scioncc,mkl-/scioncc,scionrep/scioncc,crchemist/scioncc,scionrep/scioncc