docs: document constructors of extendible structures (#3160)

* docs: document constructors of extendible structures

* docs(ClientPresence): document default value for data parameter

Co-Authored-By: SpaceEEC <spaceeec@yahoo.com>

* docs(Presence): document default value for data parameter

Co-Authored-By: SpaceEEC <spaceeec@yahoo.com>

* docs(DMChannel): capitalize DM in the constructor doc

src/structures/DMChannel.js

@@ -10,6 +10,10 @@ const MessageStore = require('../stores/MessageStore');
  * @implements {TextBasedChannel}
  */
 class DMChannel extends Channel {
+  /**
+   * @param {Client} client The instantiating client
+   * @param {Object} data The data for the DM channel
+   */
   constructor(client, data) {
     super(client, data);
     // Override the channel type so partials have a known type