Set window size option

[Vosjedev]

Hi! I would like to have an option to set the window size either in the config or as commandline argument. Being able to set the window location when that wayland protocol arrives would be nice as well.

This is because I am using tinywl as compositor for regreet. It opens regreet as window on my laptop, which is smaller, but regreet is sized to the size of my external monitor. So I tried without any background image. That made the window small, but smaller than the 'popup' for user and session. I had to resize it to see the total thing.

I will try to make some screenshots and attach those in a moment.

tinywl didn't support screenshots, but I took 2 photos with my phone. Here they are: (No background: window to small) (with background: window to big)