articulate.ly: command to start trills on the lower note?

[James Harkins]

I was just toying with articulate.ly, to hear some trills, when I noticed 
that it's starting the trill on the upper note. This is appropriate for 
older music but dead wrong for contemporary music. (If not "dead wrong," 
then certainly "generally wrong.")

How to configure this?

\include "articulate.ly"

\score {
 \unfoldRepeats \articulate { c'1\trill }
}

hjh