Revised slides

part-3-installation.md

-# Installation
+## Installation
 
 <img src="img/github_app.png" class="as-is" height="300" />
 
@@ -22,4 +22,4 @@ $ git config -l
 ```shell
 $ git --version
 # git version 1.8.5
-```
\ No newline at end of file
+```

part-4-first-repo.md

 ## The 5 commands
 
-## Mon premier dépôt
-
 ```shell
 $ git init
 $ git status

part-8-thanks.md

-# Merci!
-
 ### Laurent Heirendt
 
 ![](https://avatars0.githubusercontent.com/u/20812112?v=3&s=180)