Fix a module definition typo in the channels docs
Fix a module definition typo in the channels docs

Just a little something I stumbled upon reading the channels docs.

Joe-noh/phoenix,wsmoak/phoenix,stevedomin/phoenix,dmarkow/phoenix,evax/phoenix,Joe-noh/phoenix,michalmuskala/phoenix,ybur-yug/phoenix,mschae/phoenix,rafbgarcia/phoenix,ybur-yug/phoenix,jamilabreu/phoenix,CultivateHQ/phoenix,bsmr-erlang/phoenix,Ben-Evolently/phoenix,michalmuskala/phoenix,gjaldon/phoenix,jwarwick/phoenix,korobkov/phoenix,mschae/phoenix,Gazler/phoenix,nshafer/phoenix,nshafer/phoenix,rafbgarcia/phoenix,phoenixframework/phoenix,jwarwick/phoenix,cas27/phoenix,Kosmas/phoenix,mobileoverlord/phoenix,evax/phoenix,0x00evil/phoenix,optikfluffel/phoenix,optikfluffel/phoenix,trarbr/phoenix,dmarkow/phoenix,jamilabreu/phoenix,pap/phoenix,keathley/phoenix,mitchellhenke/phoenix,wsmoak/phoenix,mitchellhenke/phoenix,korobkov/phoenix,CultivateHQ/phoenix,ericmj/phoenix,cas27/phoenix,iStefo/phoenix,stevedomin/phoenix,Kosmas/phoenix,trarbr/phoenix,pap/phoenix,0x00evil/phoenix,0x00evil/phoenix,optikfluffel/phoenix,eksperimental/phoenix,rafbgarcia/phoenix,nshafer/phoenix,keathley/phoenix,phoenixframework/phoenix,iStefo/phoenix,phoenixframework/phoenix,bsmr-erlang/phoenix,gjaldon/phoenix,eksperimental/phoenix,Gazler/phoenix,ericmj/phoenix,mobileoverlord/phoenix