Improve rst dev install docs
Improve rst dev install docs

SiccarPoint/landlab,Carralex/landlab,landlab/landlab,ManuSchmi88/landlab,ManuSchmi88/landlab,RondaStrauch/landlab,csherwood-usgs/landlab,cmshobe/landlab,ManuSchmi88/landlab,SiccarPoint/landlab,RondaStrauch/landlab,landlab/landlab,cmshobe/landlab,cmshobe/landlab,laijingtao/landlab,laijingtao/landlab,amandersillinois/landlab,Carralex/landlab,Carralex/landlab,amandersillinois/landlab,RondaStrauch/landlab,csherwood-usgs/landlab,landlab/landlab