Update related to example docstrings

developer/doc_development/doc_development.tex

@@ -237,7 +237,7 @@ \section{Examples}
     \item By default, the first image is used as \alert{thumbnail picture}. To use e.g. the third: %$n$\textsuperscript{rd} image:%, write (preferably right above the code that produces the image):
 
     \texttt{\# sphinx\_gallery\_thumbnail\_number = 3} (ideally right above the plot code)
-    \item In the \alert{script docstring}, \LaTeX{} backslashes \texttt{\textbackslash} need to be doubled: \texttt{\textbackslash\textbackslash}
+    \item The \alert{script docstring} must be prefixed by the letter \texttt{r}.
 \end{itemize}
 
 \end{frame}