MultiIndex does not work with matplotlib

[cheremovsky]

When table_conversion='matplotlib' is used multi-indexed dataframes are rendered incorrectly — multiindex is getting rolled back to the columns — as if I called .reset_index() dfi.export(last_reses, 'dream_strats.png', table_conversion='matplotlib')

How it looks:

How it should look:

[PaleNeutron]

It is as designed.

Multi-index calculation is too complex for current simulation way in matplotlib. But it will work in any browser convert method.

I am glad to accept a PR if you can provide an implementation.