Improve title of cdf document

documents/normal-distribution/normal-distribution.tex

@@ -12,7 +12,7 @@
 
 \begin{document}
     \pagenumbering{gobble}
-    \section*{Normal distribution cumulative distribution function (CDF)}
+    \section*{Cumulative distribution function (CDF) of the normal distribution}
 
 \pgfmathdeclarefunction{gauss}{3}{%
   \pgfmathparse{1/(#3*sqrt(2*pi))*exp(-((#1-#2)^2)/(2*#3^2))}%