Take into account suggestions of Emmanuel

This includes an important change in the code since one cannot reuse a variable name in a nested block (this means that if a variable is declared, one cannot declare a variable with a same name even in a nested block, while the first variable exists).

doc/userdoc.org

@@ -28,6 +28,8 @@
 #+LATEX_HEADER_EXTRA: \usepackage{amssymb}
 #+LATEX_HEADER_EXTRA: \usepackage{xcolor}
 #+LATEX_HEADER_EXTRA: \usepackage{mdframed}
+#+LATEX_HEADER_EXTRA: \usepackage{mathpazo}
+#+LATEX_HEADER_EXTRA: \usepackage{inconsolata}
 
 #+LATEX_HEADER_EXTRA: \BeforeBeginEnvironment{tabular}{\rowcolors[]{2}{orange!5}{orange!10}}
 #+LATEX_HEADER_EXTRA: \BeforeBeginEnvironment{minted}{\begin{mdframed}[linecolor=blue,backgroundcolor=blue!10]}
@@ -41,7 +43,10 @@
 #+LATEX_HEADER_EXTRA: \BeforeBeginEnvironment{warning}{\begin{mdframed}[linecolor=red,backgroundcolor=red!10]}
 #+LATEX_HEADER_EXTRA: \AfterEndEnvironment{warning}{\end{mdframed}}
 
-#+LATEX_HEADER_EXTRA: \usepackage{mathpazo}
+#+begin_src latex :exports results
+  \let\OldTexttt\texttt
+  \renewcommand{\texttt}[1]{\fcolorbox{gray!50}{gray!5}{\OldTexttt{#1}}}
+#+end_src
 
 * Introduction