no doc related to hearbeat use case when connection is for push only events #492

right now according to doc you have to read from connection to fire SetPongHandler event. But if the websocket is used for push only it won't be fired. Solution is to use:

go ws.NextReader()

But the doc is not very straight forward about that. In my opinion there should be description of how to setup heartbeat in case of push only usage. Let me know if you need help with that.