Replace _ with - in short links (#560)
Replace _ with - in short links (#560)

Turns out the bssw.io renderer takes Markdown like 'avoid-force-push' and
replaces it essentally with the HTML 'avoid<em>force</em>'.  That defects the
purpose of these superscript short-link names.

betterscientificsoftware/betterscientificsoftware.github.io