Moved module-level docs into class docs.
Moved module-level docs into class docs.

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