Update setup.md to make people checkout on the right branch

deploy/setup.md

@@ -7,6 +7,7 @@ sudo su
 mkdir -p /var/www
 cd /var/www
 git clone https://gitlab.viarezo.fr/<login>/cicd.git # Et on clone son fork
+git checkout tp3
 ```
 
 ## Installe les dépendances