Update doc/usermanuals/DD4hep/chapters/basics.tex

Co-authored-by: Marko Petric <marko.petric@cern.ch>

doc/usermanuals/DD4hep/chapters/basics.tex

@@ -1264,7 +1264,7 @@ The corrsponding XML snippet looks like this:
 \end{minted}
 
 \item For a boolean shape the xml snippet is nested and contains 2 shape descriptions:
-\begin{minted}[frame=single,framesep=3pt,breaklines=true,tabsize=2,linenos,fontsize=\small]{c++}
+\begin{minted}[frame=single,framesep=3pt,breaklines=true,tabsize=2,linenos,fontsize=\small]{xml}
   <some_element type="BooleanShape" operation="value">
     <shape ....description of left hand shape/>
     <shape ....description of right hand shape/>