add warning or info for users that apt is not supposed to be used for updates

[Danfro]

Many new users try to use apt for updating their system - and of course fail. We need to provide them with information that UT is NOT Ubunut desktop and updates work differently here.

From some discussions in Telegram, there are two options:

• an apt wrapper is likely easier for a quick implementation
• an UI popup is technically possible and better for explaining

I would suggest we (someone) do the simple thing first and improve with UI when possible. This can be done maybe by adding an apt shell script (and symlink apt-get) in /usr/local/bin might work as Alan suggested. But where/which repo? :thinking: