Run limited first-setup when a new user is created

[matbme]

When a newly created user logs in, first-setup should appear again, but with the new-user flag so that it only prompts for the packages they want to install.

Idea: We could add an autostart rule in /etc after running first-setup for the first-time (right after installing the system) and have it check whether the user has already completed the first-setup process. If this is the case, then first-setup doesn't run, otherwise it runs with the new-user flag.

[mirkobrombin]

We can use the /etc/skel directory to add the autostart entry in the user's home directory.

[axtloss]

We can use the /etc/skel directory to add the autostart entry in the user's home directory.

No need, we can just use /etc/xdg/autostart to apply the autostart globally for every user.

[mirkobrombin]

Makes sense

[muhdsalm]

This is an issue with https://github.com/Vanilla-OS/desktop-image, isn't it?