Fade out on shutdown

## Prerequisites
- [x] I have searched open and closed issues for duplicates.

## Feature
**Is your feature request related to a problem? Please describe.**

Feature request is not related to a problem.

**Describe the solution you'd like**

It’s a little jarring when you go to shut down the computer, and you see the screen go black with parts of open windows there for a split second.
Maybe a fade to black before the shutdown command is issued could work to add a little bit of polish.

**Existing work**

Can’t find any alternatives. I know Windows has a fade through black to a shutdown screen then shuts off the display, but you can’t really port that over easily at the moment...

I could try making it myself, but I don’t believe I have enough experience yet to do that with enough finesse.

If this is the wrong place to post the issue, please let me know where a better place would be, and I’ll happily move it over there.