Change CTA document to use Paratype font family

More comfortable to read and follows CERN typographic guidelines
http://ux.web.cern.ch/assets/typography

doc/latex/cta.tex

@@ -15,15 +15,22 @@
 \fi
 \graphicspath{{../images/}}
 
+% Fonts
+
+\usepackage{paratype}
 \usepackage[T1]{fontenc}
+\usepackage[amssymb]{SIunits}
+
 \usepackage[top=2cm, bottom=2cm, left=2cm, right=2cm]{geometry}
 \usepackage{multirow}
 \usepackage[table]{xcolor}
 \usepackage{parskip}
 \usepackage{moreverb}
+
+% TikZ
+
 \usepackage{tikz}
 \usepackage{tikz-uml} % See README.md
-\usepackage{SIunits}
 \usetikzlibrary{positioning}
 
 % Hyperlinks