regolith should show warning before going to sleep/suspend

[tuanbass]

Lots of the time, I sit in front of my monitor without touching my keyboard, just to think about something. Or maybe I present something to my colleague.

And it's really annoy for me, when my computer going to sleep without any warning.

Expectation: A warning message should be shown

[SoumyaRanjanPatnaik]

Sorry for the late response. I suppose turning off the display a few seconds before suspending would be a better alternative, as that would be consistent with the behaviour of most other Desktop Environments, including Gnome.