Update doc/tutorial/intro-to-autoinstall.rst

Co-authored-by: Chad Smith <chad.smith@canonical.com>

doc/tutorial/intro-to-autoinstall.rst

@@ -98,14 +98,17 @@ level.
 Cloud-init and autoinstall interaction
 ======================================
 
-While cloud-init may provide the autoinstall configuration to the
-Ubuntu installer, it does not process the autoinstall itself.
+Cloud-init runs in both the ephemeral system, during install, and in the target system during first boot. Cloud-init then becomes inert for every subsequent
+reboot.
 
-If cloud-init directives are intended to modify the ephemeral system, they
-must appear at the top level of the cloud-config. If instead
-cloud-init directives are intended to modify the system being installed, they
-must appear under a :code:`user-data` section in :code:`autoinstall`.
+While cloud-init may provide the autoinstall configuration to the
+Ubuntu installer, it does not process the autoinstall directives
+itself.
 
+To modify the ephemeral system with cloud-init, any :external+cloud-init:ref:`#cloud-config module schema keys<modules>` can
+be provided. If instead cloud-init directives are intended to modify the system
+being installed, they must appear under a :code:`user-data:` section under
+:code:`autoinstall:`.
 .. code-block:: yaml
 
     #cloud-config