message: add(types): attachments field to EditMessage
  * feat(types): add attachments field to EditMessage
  Reference:
diff: import { Embed } from "../embeds/embed.ts";
  import { AllowedMentions } from "./allowed_mentions.ts";
  +import { Attachment } from "./attachment.ts";
  /** https://discord.com/developers/docs/resources/channel#edit-message-json-params */
  export interface EditMessage {
  @@ -11,4 +12,6 @@ export interface EditMessage {
  flags?: 4 | null;
  /** Allowed mentions for the message */
  allowedMentions?: AllowedMentions | null;
  + /** Attached files to keep */
  + attachments?: Attachment | null;
  }
  