Documentation update.

INSTALL

@@ -27,6 +27,7 @@ Download the latest Modoboa's tarball and extract it::
 
   $ tar xzf modoboa-<version>.tar.gz
   $ mv modoboa-<version> modoboa
+  $ cd modoboa
 
 Then, enter the *modoboa* directory, create a *settings.py* file (you
 can use *settings-sample.py* as a model). Specify database relative
@@ -51,6 +52,10 @@ existing migrations like this::
 
   $ python manage.py migrate
 
+Finally, create the ``scripts`` directory::
+
+  $ mkdir scripts
+
 Time zone and language
 ----------------------