How do you add the drawings?

[bravegag]

Thanks for this project! how do you add the drawings? I could not find the info anywhere. The only thing I found was how to add subfloating this bit:
%% FOR SUBFLOATS: Make sure to add the following:
%% \addtocounter{figure}{1}
%% \setcounter{subfigure}{0}

but no idea how to simply add the drawings that I have labelled fig1.png fig2.png etc