README: include a section on intended usage pattern

[ottok]

Currently the README is focused on explaining the keyboard shortcuts, features, and configuration settings. That is done well, including embedded videos.

However, before I start reading about how to configure my setup, I would like to understand what the "correct" way to use PaperWM is. At the very beginning of the README should be a section describing typical usage.

I read about Niri and ended up installing PaperWM as I was fascinated by the idea, but now after trying to use it for some time, it does not feel that efficient. I wish the README had a section that would walk through a typical "day of a user", starting from an empty desktop, and what happens when you open the first window. Will it automatically use all the screen space? No, this is not a tiling manager, but a scrolling manager, so the first window will be narrower than the full screen. Will it be placed in the center of the screen or on either edge, leaving half of the screen empty? Will all windows open up using the same size? It seems all windows always use 100% of the height, but width varies - when I open a browser window, it uses 50% of the screen, but then when I open a terminal, it uses ~30% of the screen. Where do the sizes come from, Gnome? Are users expected to configure PaperWM with custom default window sizes for all their favorite apps?

Then, as the "day of a user" continues, they may open an email client and want to focus fully on reading and replying to email. That window probably should be opened in a new desktop with no other windows and have it centered? And when the example user starts coding a web app, they likely want to have a split-screen setup with the editor and browser side-by-side in a 50/50 setup? Does the user need to start the apps in a specific way to get this? Or does PaperWM automatically switch from the first window being alone and centered to two windows being on a workspace side-by-side?

And if the day continues and the user opens their password manager to occasionally jump to it but mostly keep it in the background, should they have that on a separate workspace or as the third window on the main workspace? What will the layout be? Or open it to the scratch area?

I don't expect the README "intended usage" section to explain everything, but it would be very helpful if it told the story of "a day of a user" in one specific example, perhaps how the author himself typically uses PaperWM. If I understand how one user uses PaperWM "as intended", it will be much easier for new users to get into PaperWM using the correct patterns.