Fix small typo in Presence docs
Fix small typo in Presence docs

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