Volume stuff docs fixes (#1354)

* Volume stuff docs fixes

* 10/10 for spelling

src/client/voice/VoiceBroadcast.js

@@ -13,7 +13,7 @@ const ffmpegArguments = [
 
 /**
  * A voice broadcast can be played across multiple voice connections for improved shared-stream efficiency.
- * @extends {EventEmitter}
+ * @implements {VolumeInterface}
  */
 class VoiceBroadcast extends VolumeInterface {
   constructor(client) {

src/client/voice/dispatcher/StreamDispatcher.js

@@ -15,7 +15,7 @@ nonce.fill(0);
  *   const dispatcher = connection.playFile('./file.mp3');
  * });
  * ```
- * @extends {EventEmitter}
+ * @implements {VolumeInterface}
  */
 class StreamDispatcher extends VolumeInterface {
   constructor(player, stream, streamOptions) {

src/client/voice/util/VolumeInterface.js

@@ -1,5 +1,9 @@
 const EventEmitter = require('events');
 
+/**
+ * An interface class for volume transformation.
+ * @extends {EventEmitter}
+ */
 class VolumeInterface extends EventEmitter {
   constructor({ volume = 0 } = {}) {
     super();