[Feature] add a launch option to launch only in tray/background

[Yeethan69]

This way, we can make it launch on session load, but not pop up a window. Would be a good feature to add imo.

[coldfix]

Hey. Yes, sounds reasonable. I want to make some changes in the way that acolyte is executed and this could be one of them. But could take me a while to get to it, so no promises when it's done.