Fix documentation

Author: nuclearace

Source/SocketIO/Client/SocketIOClient.swift

@@ -296,7 +296,7 @@ open class SocketIOClient : NSObject, SocketIOClientSpec, SocketEngineClient, So
     /// Same as emit, but meant for Objective-C
     ///
     /// - parameter event: The event to send.
-    /// - parameter with: The items to send with this event. May be left out.
+    /// - parameter with: The items to send with this event. Send an empty array to send no data.
     @objc
     open func emit(_ event: String, with items: [Any]) {
         guard status == .connected else {