Added Client#status and Message#type typedefs (#1571)

* typedef for MessageTypes and linked Client#status to Status

* should be singular

* typedef for Voiceconnection#status

src/structures/Message.js

@@ -40,7 +40,7 @@ class Message {
 
     /**
      * The type of the message
-     * @type {string}
+     * @type {MessageType}
      */
     this.type = Constants.MessageTypes[data.type];