README: document multiple destinations for match rules
README: document multiple destinations for match rules

lyft/carbon-c-relay,grobian/carbon-c-relay,lyft/carbon-c-relay,piotr1212/carbon-c-relay,piotr1212/carbon-c-relay,piotr1212/carbon-c-relay,grobian/carbon-c-relay,grobian/carbon-c-relay,lyft/carbon-c-relay,piotr1212/carbon-c-relay