add callout boxes for commentary

layout.sty

@@ -42,6 +42,7 @@
   \usetikzlibrary{intersections}% for very fancy borders with intersecting lines
   \usetikzlibrary{decorations.text}% for text along circle paths in cs
   \usetikzlibrary{shapes.misc}% for very fancy \section
+  \usetikzlibrary{shapes.callouts}% for labels on the cs
   \usetikzlibrary{patterns}% for the pattern 'gridspecks'
 \RequirePackage{pifont}
 \RequirePackage{colortbl}