Remove shading effects from menu items

[wendeldw]

Please consider removing the shading effects from the stylesheet. Although it is a matter of personal taste, nowadays looks are leading towards flat design.

[PaulL1]

It would probably be nice to make it switchable, although I'm not sure if maybe it's just easier for people to override the style in their css.

[PaulL1]

This is a useful request, but not really in the current roadmap. We have far too many good ideas in the repository already, giving the impression that we have a project riven with defects.

Accordingly, I am leaving the enhancement tag on this, but closing it. If someone would like this functionality, we'd welcome a pull request that adds it.