improve presentation and fix tp.md

presentation.tex

@@ -4,7 +4,7 @@
 \subtitle{learning to work with Git, alone or in collaboration}
 \author[laurent.modolo@ens-lyon.fr]{Laurent Modolo$^{1}$}
 \institute[]{$^{1}$LBMC UMR 5239 -- CNRS/ENS Lyon}
-\date[27 October 2017]{27 October 2017}
+\date[7 March 2017]{7 March 2017}
 \subject{learning to work with Git, alone or in collaboration}
 
 \begin{document}
@@ -333,6 +333,13 @@ git creates a new blob for the new \mintinline{sh}{data/number.txt}\\[0.5em]
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \subsection{Committing change to Git}
 
+\begin{frame}
+  \frametitle{git areas}
+  \begin{center}
+    \includegraphics[width=\textwidth]{./img/three_git_areas.png}\\
+  \end{center}
+\end{frame}
+
 \begin{frame}[fragile]
   \frametitle{git commit}
 \begin{shcode}

tp.md

@@ -94,7 +94,7 @@ To test your connection run:
 ```sh
 ssh -Tv gitlab_lbmc
 ```
-§
+
 ### the https method (for the PSMN computers)
 
 When you cannot modify the `~/.ssh/config` you can use the https protocol