Add snowflake utils (#1064)

* snowflakes

* use proper binary for snowflake example

* fix jsdoc errors

* remove dupe

src/structures/GroupDMChannel.js

@@ -61,7 +61,7 @@ class GroupDMChannel extends Channel {
     if (!this.recipients) {
       /**
        * A collection of the recipients of this DM, mapped by their ID.
-       * @type {Collection<string, User>}
+       * @type {Collection<Snowflake, User>}
        */
       this.recipients = new Collection();
     }