Make help for --rtmpdump more clear.
Make help for --rtmpdump more clear.

Feverqwe/livestreamer,Masaz-/livestreamer,gtmanfred/livestreamer,bastimeyer/streamlink,wolftankk/livestreamer,jtsymon/livestreamer,flijloku/livestreamer,wlerin/streamlink,lyhiving/livestreamer,blxd/livestreamer,breunigs/livestreamer,beardypig/streamlink,okaywit/livestreamer,streamlink/streamlink,ethanhlc/streamlink,Dobatymo/livestreamer,Saturn/livestreamer,bastimeyer/streamlink,mmetak/streamlink,okaywit/livestreamer,sbstp/streamlink,beardypig/streamlink,intact/livestreamer,gravyboat/streamlink,wolftankk/livestreamer,chrippa/livestreamer,charmander/livestreamer,chhe/livestreamer,jtsymon/livestreamer,programming086/livestreamer,back-to/streamlink,streamlink/streamlink,lyhiving/livestreamer,melmorabity/streamlink,gravyboat/streamlink,chrippa/livestreamer,caorong/livestreamer,Dobatymo/livestreamer,blxd/livestreamer,chhe/streamlink,back-to/streamlink,breunigs/livestreamer,fishscene/streamlink,charmander/livestreamer,asermax/livestreamer,mmetak/streamlink,chhe/streamlink,chhe/livestreamer,gtmanfred/livestreamer,javiercantero/streamlink,derrod/livestreamer,Klaudit/livestreamer,fishscene/streamlink,caorong/livestreamer,derrod/livestreamer,programming086/livestreamer,wlerin/streamlink,Masaz-/livestreamer,Klaudit/livestreamer,melmorabity/streamlink,javiercantero/streamlink,sbstp/streamlink,ethanhlc/streamlink,flijloku/livestreamer,hmit/livestreamer,intact/livestreamer,chrisnicholls/livestreamer,hmit/livestreamer,Feverqwe/livestreamer,Saturn/livestreamer