fix: Fixed error in the script as well as in the readme

README.md

@@ -2,19 +2,20 @@
 
 ## Installation
 
-**WARNING** installer considers that '~/afs/' exists
+**WARNING** Make sure to backup all your important dotfiles before running that
+Note: installer considers that '~/afs/' exists
 
-'''sh
+```sh
 git clone https://forge.oblic-parallels.fr/guillm/boussole.git
 cd boussole
 ./install.sh
-'''
+```
 
 ## Uninstallation
 
 **WARNING** This will reset all your config files in your AFS
 
-'''sh
+```sh
 cd ~/afs
 git restore .
-'''
+```