update latex generation blockquote to use somethng else than verbatim

[Ducasse]

For this we need to introduce

\usepackage[many]{tcolorbox}  % For colored boxes

% Define a new environment called "boxB"
\newenvironment{boxB}{
  \begin{tcolorbox}[colback=white, colframe=black, rounded corners]
}{
  \end{tcolorbox}
}

in the template