added phi-enriched minbias decfile
adding a phi-enriched minbias decfile, analogous to https://gitlab.cern.ch/lhcb-datapkg/Gen/DecFiles/-/blob/v30r58/dkfiles/minbias=BiasedLambdaPt300MeV.dec
adding a phi-enriched minbias decfile, analogous to https://gitlab.cern.ch/lhcb-datapkg/Gen/DecFiles/-/blob/v30r58/dkfiles/minbias=BiasedLambdaPt300MeV.dec