Dash - The "press enter to launch the first search result" behavior needs a visual hint

[tbys]

In the Dash, when you enter a search term and hit enter right away, the top-leftmost item is launched per default. This is great and just what I want.

However, this feature has no visual hint, which means I only discovered it yesterday (despite using Unity since its inception).

I suggest that you add the mouseover effect (the whiteish semitransparent background) to the first search result (the one that will be launched on hitting enter).