Add CI Interval to boxplot notch documentation

[mame98]

Problem

The boxplot Method allows to show the confidence interval around the median by using the notch parameter. However there is no documentation on which ci is used, I assume it is the 95% CI or did I miss something?

Suggested Improvement

At least document which confidence interval is used. Maybe one could consider adding a Parameter to specify A confidence interval?

[jklymak]

Its set by conf_intervals isn't it?

[mame98]

Yeah, i dont know how I missed that 🤦

However I still think there should be a clarification what the default CI is?

[jklymak]

Maybe? And the notch description should refer to conf_interval also as well?

[QuLogic]

The default is determined by bootstrap, which is mentioned in the notch docstring.