added qr code

Author: thomasWeise

text/front/preface/bookUrl.pdf

@@ -41,7 +41,6 @@ \chapter*{Preface}%
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 \begin{flushleft}%
 Copyright \textcopyright\ 2024\\[3pt]%
 Prof.~Dr.~\href{http://iao.hfuu.edu.cn/5}{Thomas Weise}~\cnPdf{profWeise}\\%
@@ -55,5 +54,12 @@ \chapter*{Preface}%
 \clearpage%
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+%
+\begin{center}%
+\includegraphics[width=7cm]{\currentDir/bookUrl}\\%
+\url{https://thomasweise.github.io/programmingWithPython/programmingWithPython.pdf}%
+\end{center}%
+%
+\strut\vfill\strut%
 This book was built using the following software:%
 \gitOutputRaw{}{}{scripts/dependencyVersions.sh}{versions}{}%