Add Guild.voiceConnection and VoiceChannel.connection

src/structures/Guild.js

@@ -661,6 +661,16 @@ class Guild {
       }
     }
   }
+
+  /**
+   * If the client is connected to any voice channel in this guild, this will be the relevant
+   * VoiceConnection.
+   * @type {VoiceConnection}
+   * @readonly
+   */
+  get voiceConnection() {
+    return this.client.voice.connections.get(this.id);
+  }
 }
 
 module.exports = Guild;