Wobbly Windows on by default for SteamOS 3

[CKWarner]

Since SteamOS 3 will be using KDE, I think it would be a good idea to have the Wobbly Windows effect on by default.

It's a very unobtrusive effect, only kicking in when a window is moved. Since the users of SteamOS are going to necessarily be playful, I think it would be a nice way to introduce them to the freedom to experiment that they'll get with SteamOS.