Update README for new domain URL setting.
Update README for new domain URL setting.

Splaktar/boomerang,gdgphilippines/boomerang,GDG-Boston/boomerang,GDGGhana/GDGGhana.github.io,GDG-Dusseldorf/gdg-dusseldorf.github.io,GDGGhana/GDGGhana.github.io,GDGLegon/GDGLegon.github.io,GDG-Senador-Canedo/gdg-senador-canedo.github.io,GDG-Senador-Canedo/gdg-senador-canedo.github.io,gdgphilippines/main,jhoon/boomerang,GDG-Goiania/gdg-goiania.github.io,gdgphilippines/boomerang,gdgakure/boomerang,gdgphilippines/main,GDGLegon/GDGLegon.github.io,gdgphilippines/main,BruGTUG/BruGTUG.github.io,GDGWellington/GDGWellington.github.io,GDGLima/boomerang,gdgphilippines/boomerang,emedinaa/boomerang,GDG-Dusseldorf/gdg-dusseldorf.github.io,gdgphilippines/boomerang,GDGGhana/GDGGhana.github.io,tfmorris/boomerang,gdgberkeley/gdgberkeley.github.io,dbs/boomerang,gdgphilippines/boomerang,dbs/boomerang,tfmorris/boomerang,jhoon/boomerang,GDGGhana/GDGGhana.github.io,emedinaa/boomerang,GDGGhana/GDGGhana.github.io,gdg-x/boomerang,GDG-Goiania/gdg-goiania.github.io,GDG-Boston/boomerang,gdgakure/boomerang,gdgberkeley/gdgberkeley.github.io,BruGTUG/BruGTUG.github.io,GDG-Dusseldorf/gdg-dusseldorf.github.io,gdgphilippines/main,GDGWellington/GDGWellington.github.io,Splaktar/boomerang,gdg-x/boomerang,GDGLima/boomerang,gdgphilippines/main