Add systemctl mask method to System sleep manual page

[vitalune]

when running long terminal processes (builds, training jobs, etc.), you sometimes want to leave your computer without it shutting off so the process can complete while you're gone,

so im sharing a method to make that happen, along with suggesting that it be added to the System Sleep manual page about temporarily disabling sleep for long-running processes.

you can temporarily disable all sleep states by running this command in a terminal window:
sudo systemctl mask sleep.target suspend.target hibernate.target hybrid-sleep.target

and turn-off screensaver:
xset s off

and re-enable sleep and wallpaper by:
sudo systemctl unmask sleep.target suspend.target hibernate.target hybrid-sleep.target
xset s on
if there are any better methods please let me know, this is just the first one I thought of.