documentation for why3session

use lmodern since the -- are nicer

doc/manual.tex

@@ -3,6 +3,7 @@
 % rubber: module index
 
 \usepackage[T1]{fontenc}
+\usepackage{lmodern}
 %\usepackage{url}
 \usepackage[a4paper,pdftex,colorlinks=true,urlcolor=blue,pdfstartview=FitH]{hyperref}
 \usepackage{graphicx}