Spacemacs-style Contour Separator

[davidzchen]

I'm a big fan of Spacemacs, and I especially like how the interface looks with the contour separator style (see "13.4.2 Separators" in the documentation. For example:

Any chance you could add the contour-style separator symbols?

Ideally, it would be nice to support all of the separator symbols that Spacemacs supports. I would be happy to help, but I'm do not have any experience with making font glyphs.