keep themes/styles distinction like Window Maker

[tidux]

From the docs:

"a Theme is a Style that includes a Background"

https://www.windowmaker.org/docs/guidedtour/back.html

[phkaeser]

@tidux -- to be honest, I had found that "Style" vs "Theme" distinction a bit confusing; and my initial take was to move along with just "Themes". Background optional.

Since this seems important to you: What's the rationale for keeping these distinct?

[tidux]

My rationale for keeping them distinct is Window Maker theme/style compatibility. If that's not a design goal this would be out of scope.