Closes #368 ~

To reiterate my original comment and my approach for the icon design (adjusted the proportions to that of a square Morewaita icon):

not sure what's GNOME HIG's policy on icons whose body are not supposed to have depth / mass, like a piece of paper, a sticky note or a DNA helix, in this case. We might have to consult @somepaulo for this one, but we can at least tweak the proportions to that of an GNOME HIG icon

Feel free to modify, of course.