Show distribution mean and sd (and higher moments?)

[tadamcz]

• mean
• sd

Potentially could add the following, but this might lead to information overload:

• variance (we don't know if users will prefer the variance or the sd)
• skewness
• kurtosis

[tadamcz]

Closed by https://github.com/usedagger/usedagger.io/commit/223ac089