Adding link to `Apps and Games` page from Side Bar at fsharp.org

I just noticed there is scant linkage to the webpage we just changed - http://fsharp.org/use/ios/ . The only link I could find was on this page - http://fsharp.org/use/ios/

I think this page should be more prominently displayed, perhaps on the side-bar under `Contributing` below `F# Community Projects`. Here is a patch that does so (I think... you better test it first :))