add doc about password to provide to ansible

README.md

@@ -65,6 +65,8 @@ then run it
 ```
 ansible-playbook --limit prod -u formateur --ask-pass --ask-become-pass --become phylogeny.yml
 ```
+You will be ask for the *formateur* user (SSH password) then the *sudo* password (BECOME password).
+ 
 If you want to play only one or a set of playbook see available tags in phylogeny.yml
 
 then run