minor cleanup of environment-modules documentation (#814)
minor cleanup of environment-modules documentation (#814)

* minor cleanup of environment-modules documentation

* environment modules: update usage instructions

LLNL/spack,LLNL/spack,krafczyk/spack,krafczyk/spack,krafczyk/spack,tmerrick1/spack,matthiasdiener/spack,mfherbst/spack,tmerrick1/spack,lgarren/spack,lgarren/spack,TheTimmy/spack,skosukhin/spack,mfherbst/spack,EmreAtes/spack,iulian787/spack,EmreAtes/spack,iulian787/spack,TheTimmy/spack,matthiasdiener/spack,tmerrick1/spack,iulian787/spack,tmerrick1/spack,iulian787/spack,TheTimmy/spack,mfherbst/spack,EmreAtes/spack,matthiasdiener/spack,krafczyk/spack,matthiasdiener/spack,krafczyk/spack,matthiasdiener/spack,TheTimmy/spack,EmreAtes/spack,mfherbst/spack,lgarren/spack,skosukhin/spack,LLNL/spack,LLNL/spack,skosukhin/spack,skosukhin/spack,tmerrick1/spack,skosukhin/spack,lgarren/spack,TheTimmy/spack,LLNL/spack,mfherbst/spack,lgarren/spack,iulian787/spack,EmreAtes/spack