text: Title: `solara.DataFrame` doesn't display row index names
  Body: Here's the default display of a dataframe in a Jupyter notebook:
  
  ![image](https://github.com/widgetti/solara/assets/1813121/e44f561a-74fe-4ebc-86bb-6c5f1a173bb5)
  
  Here's how solara displays it:
  
  ![image](https://github.com/widgetti/solara/assets/1813121/cb74cb28-6617-4911-880e-7532e8b41185)
  
  In the second display of the transposed dataframe the row names should be `a, b, c, d` instead of `0, 1, 2, 3`.