text: Title: Loading indicator needs to be shown for longer
  Body: I have a notebook that I've published via github pages.  It's very nice, and marimo does a wonderful job.  But a number of people who have visited have said that they thought it was broken because it initially showed a spinning circle saying "Initializing...", etc., but that circle disappeared, leaving just a white page.  The problem is that there's a lag of up to 8 seconds between the spinning circle and the spinning hourglass (which is followed by actual content).  And I guess that's just long enough for people to think the page must be broken.  We all have pretty beefy machines with high-speed internet.
  
  If that spinning circle could just be kept on the screen until other elements start to load, I think it would be perfect.
  
  For reference, my published notebook is [here](https://moble.github.io/sxscatalog/), and the raw notebook itself is [here](https://github.com/moble/sxscatalog/blob/main/scripts/catalog_notebook.py).
  
  (And thanks again for the wonderful package.  It's really amazing.)