compare_intra method should limit the name parameter length to 2

Hi, I was just exploring your package and I found the compare_intra feature pretty interesting. So, just thought it would be better if we can limit the `names` tuple size to 2.
my_report = sv.compare_intra(source_df=df, condition_series=df["Type"] == "SUV", names=['SUV', 'Sedan', 'Sports Car', 'Wagon', 'Minivan'])