feat(Message): allow removing attachments (#5557)

src/structures/APIMessage.js

@@ -196,6 +196,7 @@ class APIMessage {
         typeof content === 'undefined' && typeof message_reference === 'undefined' ? undefined : allowedMentions,
       flags,
       message_reference,
+      attachments: this.options.attachments,
     };
     return this;
   }

src/structures/Message.js

@@ -478,6 +478,7 @@ class Message extends Base {
    * @property {string|boolean} [code] Language for optional codeblock formatting to apply
    * @property {MessageMentionOptions} [allowedMentions] Which mentions should be parsed from the message content
    * @property {MessageFlags} [flags] Which flags to set for the message. Only `SUPPRESS_EMBEDS` can be edited.
+   * @property {MessageAttachment[]} [attachments] The new attachments of the message (can only be removed, not added)
    */
 
   /**
@@ -656,6 +657,14 @@ class Message extends Base {
     return this.edit({ flags });
   }
 
+  /**
+   * Removes the attachments from this message.
+   * @returns {Promise<Message>}
+   */
+  removeAttachments() {
+    return this.edit({ attachments: [] });
+  }
+
   /**
    * Used mainly internally. Whether two messages are identical in properties. If you want to compare messages
    * without checking all the properties, use `message.id === message2.id`, which is much more efficient. This