Errorbands possible?

[blankclemens]

Hello and thank you for the great extension to errorbars, I do wonder however if it is possible to have an errorband on a line instead errorbars? With hundreds of points it makes sense to have a smoothing line on top and bottom for the errors. If not, would it be possible to include, or do you have an idea to implement this?

Thank you very much! (First time on github, please forgive me if this is not the right place or style to ask for features).

Cheers, Clemens