doc/arch.md: update
doc/arch.md: update

osrg/earthquake,osrg/earthquake,osrg/namazu,osrg/namazu,osrg/earthquake,osrg/namazu,osrg/earthquake,osrg/namazu,osrg/namazu,osrg/namazu,osrg/earthquake,osrg/namazu,osrg/earthquake,osrg/earthquake