update default monospace and serif font to roboto mono and slab respectively
update default monospace and serif font to roboto mono and slab respectively

Daemonite/material,moconnor-bmj/BMDL,Daemonite/material,Hexhu/KcalTech,ottoandry/tesina,Hexhu/KcalTech,moconnor-bmj/BMDL,Hexhu/KcalTech,Daemonite/material,moconnor-bmj/BMDL,ottoandry/tesina,Hexhu/KcalTech,ottoandry/tesina