Add snowflake utils (#1064)

* snowflakes

* use proper binary for snowflake example

* fix jsdoc errors

* remove dupe

src/structures/interface/TextBasedChannel.js

@@ -11,13 +11,13 @@ class TextBasedChannel {
   constructor() {
     /**
      * A collection containing the messages sent to this channel.
-     * @type {Collection<string, Message>}
+     * @type {Collection<Snowflake, Message>}
      */
     this.messages = new Collection();
 
     /**
      * The ID of the last message in the channel, if one was sent.
-     * @type {?string}
+     * @type {?Snowflake}
      */
     this.lastMessageID = null;
   }