chore: add dynamic button for beatmap display

src/lib/presence.ts

@@ -16,4 +16,6 @@ export const updateStatus = async (status: {
   });
 export const updateUser = async (user: { username: string; id?: string | null }) =>
   await invoke('presence_update_user', { user: { username: user.username, id: user.id } });
+export const updateButton = async (button: { text?: string; url?: string }) =>
+  await invoke('presence_update_button', { button: button });
 export const isConnected = async () => await invoke<boolean>('presence_is_connected');