Create topoplotseries with additional supportive rows

[vladdez]

Additional rows could indicate confidence intervals, significance (p-values), t-values
Example: https://github.com/behinger/eegvis

[vladdez]

Should it be just example in docs or functionality of the function? @behinger

[behinger]

depends, if it is easily doable in 2-3 lines of code, then documentation seems appropriate. If it is more elaborate, than a function might be necessary. I'd prefer to make it easy to do the former rather thna the later.

Would the idea be also to "sync" such a plot with an plot_erp like in eegvis? Could be helpful

[vladdez]

done here https://unfoldtoolbox.github.io/UnfoldMakie.jl/dev/generated/how_to/uncertain_topo/