Support scikit-learn compatible

[arandomgoodguy]

Hi, great work!

Is there any chance for ExcelFormer to support scikit-learn fit API, so we can use something like ExcelFormerClassifier.fit().

In your another repo, TabCaps, model can be fitted by TabCapsClassifier.fit(), which is good.

It can help compare performance of multiple tabular models if they are all in one format, thanks!