Added more to RadixTree's README
Added more to RadixTree's README

uteschiehlen/swift-algorithm-club,raywenderlich/swift-algorithm-club,raywenderlich/swift-algorithm-club,aatalyk/swift-algorithm-club,daisysomus/swift-algorithm-club,aatalyk/swift-algorithm-club,jawwad/swift-algorithm-club,raywenderlich/swift-algorithm-club,jawwad/swift-algorithm-club,daisysomus/swift-algorithm-club,tomtclai/swift-algorithm-club,tkester/swift-algorithm-club,BenEmdon/swift-algorithm-club,eugenepavlyuk/swift-algorithm-club,boqian2000/swift-algorithm-club,eugenepavlyuk/swift-algorithm-club,hollance/swift-algorithm-club,boqian2000/swift-algorithm-club,TheIronBorn/swift-algorithm-club,uteschiehlen/swift-algorithm-club,jawwad/swift-algorithm-club,tomtclai/swift-algorithm-club,tkester/swift-algorithm-club,BenEmdon/swift-algorithm-club,TheIronBorn/swift-algorithm-club