Documentation for modules configuration options (#1685)
Documentation for modules configuration options (#1685)

This PR add documentation for the `suffixes` and `hash_length` options
for modules.yaml.

This resolves #1416.
LLNL/spack,matthiasdiener/spack,iulian787/spack,matthiasdiener/spack,iulian787/spack,skosukhin/spack,mfherbst/spack,mfherbst/spack,tmerrick1/spack,mfherbst/spack,TheTimmy/spack,TheTimmy/spack,EmreAtes/spack,matthiasdiener/spack,krafczyk/spack,TheTimmy/spack,krafczyk/spack,mfherbst/spack,EmreAtes/spack,LLNL/spack,tmerrick1/spack,krafczyk/spack,skosukhin/spack,matthiasdiener/spack,skosukhin/spack,LLNL/spack,mfherbst/spack,krafczyk/spack,lgarren/spack,krafczyk/spack,iulian787/spack,TheTimmy/spack,EmreAtes/spack,skosukhin/spack,TheTimmy/spack,lgarren/spack,lgarren/spack,LLNL/spack,EmreAtes/spack,lgarren/spack,lgarren/spack,iulian787/spack,iulian787/spack,matthiasdiener/spack,LLNL/spack,skosukhin/spack,EmreAtes/spack,tmerrick1/spack,tmerrick1/spack,tmerrick1/spack