Fixed deprecated decorator formatting.
Fixed deprecated decorator formatting.

Fixed markdown formatting in the string the deprecated decorator adds
to functions.

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