Add caching by default

[Laurin-W]

I think for the boilerplate, it makes to add default caching, like we do for mastopod now. Most apps aren't too time-critical, I suppose. We can leave a comment in the App.tsx file and set a small default.

What do you think?

const queryClient = new QueryClient({
  defaultOptions: {
    queries: {
      refetchOnWindowFocus: false,
      staleTime: 1 * 60 * 1000, // Consider data fresh for 1 minutes
      cacheTime: 30 * 60 * 1000, // Cache unused data for 30 minutes.
      retry: 3,
    },
  },
});