Add new module about maxima detection

[tischi]

@manerotoni
There seems to be a lot to learn here (at least for me)
See the discussions here:

• Enhancement of peak detection features scikit-image/scikit-image#3016
• https://forum.image.sc/t/new-maxima-finder-menu-in-fiji/25504/5

I found the concept of "prominence" always confusing, but I think this is super important!
Making a teaching module would be a good way to obtain solid understanding ;-)

[manerotoni]

Yes very good point. It is a useful feature and often I realize that I am not sure what it is exactly doing (depending on the implementation). I just use it.