refactor(helpers): separate functions into files (#667)

* refactor(helpers): separate functions into files

* idk

* idk

src/helpers/invites/get_invite.ts

@@ -0,0 +1,10 @@
+import { RequestManager } from "../../rest/request_manager.ts";
+import { InvitePayload } from "../../types/mod.ts";
+import { endpoints } from "../../util/constants.ts";
+
+/** Returns an invite for the given code. */
+export async function getInvite(inviteCode: string) {
+  const result = await RequestManager.get(endpoints.INVITE(inviteCode));
+
+  return result as InvitePayload;
+}