Kurtosis vs. Excess kurtosis

[patriciamar]

In Summary, short explanation for Kurtosis, Skewness and other characteristics could be provided, including commenting on difference between kurtosis and excess kurtosis. This should also be incorporated into pdf-html report.

[adelahladka]

I added some text. Please check it and then I'll add it also into reports.

[patriciamar]

Looks great!