Bundle certain well-known rules with PaperWM

[develop7]

Is your feature request related to a problem? Please describe.
As an user of PaperWM it's a bit annoying to witness certain windows meant to be in a scratch layer to get stacked, i.e. splash screens, "about" windows of Firefox, Telegram's "media viewer" window, etc.

Describe the solution you'd like
I'd like PaperWM to bundle winprops rules for such windows

Describe alternatives you've considered
Creating rules on my own, but is tedious and it seems like everyone should do it from scratch.

Additional context
I've created a topic in discussions to share winprops rules with the community and posted some of mine there, #971, that's where some candidates could emerge.

[KETHERCORTEX]

meant to be in a scratch layer

"Scratch layer" means "on top of everything on every workspace". When opening Firefox's "about" window, do you really want it to follow you across workspaces?

[develop7]

That's actually a very good point, and the answer is no, I don't. But I also don't want it stacked, hence the workaround.