Close "implemented" suggestions.讨论

Instead of closing it ? Yup.. I think so too. A prominent highlight should be sufficient for us to identify suggestions that have already been implemented. And if anyone would like to suggest something to improve that implementation, they still can. And maybe if there's been a suggestion for improvement of an already implemented idea, a different color or icon can be used to highlight that suggestion to indicate that an improvement has been suggested to an already implemented feature.

So to sum it up, there will be 2 types of highlights. One to indicate that a suggestion has already been implemented and the second one to indicate that a new improvement has been suggested for the said implementation. If the new suggestion is also accepted and is implemented, the highlight can be changed back to the 1st type again to indicate closure.