SATB.Ly template and putting lyrics below the staff

[Colin Campbell]

I've just discovered Trevor Daniels' satb.ly system, and huge kudos to 
him! I've tweaked a bit by adding   \consists Merge_rests_engraver to a 
Layout variable, but I'm wrestling the lyrics a bit. By default, they 
come out aligned above context; how can I get them below?

Cheers,

Colin