Added overlay color and opacity for chapter component.

[peiche]

Regarding issue 268, point 3. (The overlay part, anyway.)

[bearded-avenger]

Thanks Paul! Gonna sit on this. I really feel themes should be responsible for enhancing the view.

[michaelbeil]

There's much to be considered with a wide userbase when adding more options to ASE core, so ponder on this we shall. We always appreciate your PRs @peiche! Keep 'em coming.

[peiche]

So I ended up needing to create a pseudo-element overlay again for the content component. The interesting thing here is that the aesop-content-comp-wrap element's :after pseudo-element is already being used in a clearfix. While it didn't have any negative repercussions in this particular post, I don't think it really serves as a long-term solution, due to potential css conflicts.